JPH09208601A - Preparation of carboxymethylcellulose ether alkali metal salt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare CMC affected little by drying conditions and having various excellent properties. SOLUTION: In the production of a carboxymethylcellulose ether alkali metal salt by etherifying a cellulosic material in a water-containing organic solvent, the following relationship is satisfied: 0.85<=(A1-A2)/E<1.00 (wherein A1 is the total number of moles of the alkali used in a water-containing organic solvent having a weight ratio of the organic solvent to the water of 80:20 to 93:7; A2 is the number of moles of the alkali consumed to neutralize the etherifying agent; and E is the number of moles of the etherifying agent used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an alkali salt of carboxymethyl cellulose ether (hereinafter abbreviated as CMC). More specifically, CM that is not affected by the drying conditions when drying the reaction product and is excellent in various qualities.
Regarding the production method of C.

[0002]

2. Description of the Related Art CMC is produced by reacting cellulosic raw materials such as wood pulp and linter pulp with existing monochloroacetic acid such as alkali hydroxide, followed by neutralization, purification and drying.
Cellulose ether obtained through post-processing such as crushing, as a water-soluble polymer electrolyte thickener, dispersant, protective colloid agent, adhesive, muddy water regulator for petroleum boring, binder for fish feed, printing paste It is widely used as such.

The CMC production method is roughly classified into a water medium method using water as a reaction medium and a solvent method using an organic solvent. The solvent method can obtain alkali cellulose with a smaller amount of alkali than the water medium method. In addition, since the etherification reaction is achieved in a relatively short time, the effective utilization rate of the etherifying agent is high, and the use of a small amount of the etherifying agent is sufficient, which is an advantage.

As a production method belonging to the solvent method, Japanese Patent Publication Sho 60
-42241, Japanese Patent Publication No. 63-55523,
The method described in JP-A-3-210301 may be used.

In the method described in Japanese Patent Publication No. 60-42241, the amount of alkali obtained by subtracting the amount of alkali used for neutralizing the etherifying agent in producing CMC in a water-containing organic solvent is 1 mol of the etherifying agent. Against 0.10-0.
The etherification reaction is started in an excess system of the etherifying agent such that the amount becomes 90 mol, and then the remaining 0.90 to 0.10 mol or more of alkali is added in portions to complete the reaction, and the excess alkali is converted to acetic acid. It is a method for producing CMC having a uniform distribution of substituents by increasing the effective utilization rate of the etherifying agent by neutralizing and purifying with, and drying at 80 to 100 ° C.

Further, in the method described in Japanese Patent Publication No. 63-55523, in producing CMC in a water-containing organic solvent, a part of the etherifying agent is neutralized with an alkali hydroxide prior to the addition of the etherifying agent. This is a method for producing CMC having a uniform DS by carrying out etherification by using a product, neutralizing excess alkali with acetic acid, purifying and drying.

Further, according to the method described in JP-A-3-210301, an alkali metal monochloroacetate prepared by adding an equal amount of alkali hydroxide to monochloroacetic acid to monochloroacetic acid when producing CMC in a water-containing organic solvent. After adding a salt water-containing organic solvent solution, further carry out etherification by adding alkali hydroxide in a solid state to complete, neutralize excess alkali with acetic acid, purify, and dry to obtain a high DS. This is a method for producing high-viscosity CMC.

However, in all of the conventional production methods belonging to such a solvent method, neutralization with acetic acid or the like was required, so that a part of the carboxyl groups of the obtained CMC was inevitably in the acid form. Thus, the acid type carboxyl groups in the subsequent drying process (Cell-O-CH ₂ -CO
OH) is heated at a high temperature, an unsubstituted hydroxyl group (Cell-OH) in the molecular chain of CMC and an ether bond (Cell-O—CH ₂ —COO) with hydroxyl groups in the molecule and adjacent molecules.
-Cell) introduces a cross-linking structure, so that the qualities such as transparency and salt water resistance of the CMC aqueous solution are significantly reduced depending on the drying conditions.

Therefore, the CMC obtained from the conventional manufacturing method is
Without lowering the drying temperature to such an extent that the deterioration of quality such as transparency and salt water resistance can be suppressed, that is, extending the drying time, good quality CMC could not be obtained. I was invited.

[0010]

DISCLOSURE OF THE INVENTION The present invention is to provide a method for producing CMC which is not easily affected by the drying conditions and is excellent in various qualities.

[0011]

Means for Solving the Problems In the production of an alkali salt of carboxymethyl cellulose ether obtained by etherifying a cellulosic raw material in a water-containing organic solvent, the present inventors have found that the weight ratio of the organic solvent and water is 80. : 2
The relation between the total number of moles A1 of the alkali used and the number of moles A2 of the alkali consumed for neutralizing the etherifying agent in the water-containing organic solvent of 0 to 93: 7 is related to the number E of the etherifying agent used. It was found that the manufacturing method satisfying the formula 0.85 ≦ (A1−A2) / E <1.00 can achieve the manufacture of CMC that is not easily affected by the drying conditions and is excellent in various qualities.

As the cellulosic raw material, any linter pulp, wood pulp or the like which is usually used in the production of CMC can be used and is not particularly limited.

The water-containing organic solvent is not particularly limited as long as it is a solvent usually used in the production of CMC for etherifying a cellulosic raw material. Specifically, for example, alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol (IPA) and butyl alcohol, hydrophilic organic solvents such as ketones such as acetone and methyl ethyl ketone, or benzene, A mixture of at least one kind of a mixture of aromatic hydrocarbons such as toluene and water can be mentioned. Among these, isopropyl alcohol, methyl alcohol, and water, which are most commonly used in the production of the solvent method CMC, are used in the present production method. Is preferred. The weight ratio of isopropyl alcohol and methyl alcohol is 80:20.
It may be appropriately selected from the range of 98: 2 depending on the required quality of CMC.

As the alkali, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide and the like can be used, but sodium hydroxide is preferable for economical reasons.

As the etherifying agent, monochloroacetic acid or a partially neutralized product thereof, sodium monochloroacetate and the like can be used.

In the present invention, the weight ratio of organic solvent to water is 80:
In the water-containing organic solvent of 20 to 93: 7, the total number of moles A1 of the alkali used and the number of moles A2 of the alkali consumed for neutralizing the etherifying agent are between the number E of the etherifying agent used. It is necessary to satisfy the relational expression 0.85 ≦ (A1-A2) / E <1.00 because the organic solvent is less than 80% by weight and the water is more than 20% by weight or the organic solvent is 93% by weight. If the content is more than 7% by weight and the water content is less than 7% by weight, the CMC will be satisfied even if the relational expressions of alkali and etherifying agent defined in the present invention are satisfied.
It is not preferable because it is economically disadvantageous in that the quality of the aqueous solution such as transparency and salt water resistance is lowered and the effective utilization rate of the etherifying agent is also lowered.

The weight of the organic solvent and water is 80:20.
If the relational expression between the alkali and the etherifying agent is (A1−A2) / E <0.85 even in a water-containing organic solvent of ˜93: 7, C
It is not preferable because the transparency of the MC aqueous solution is reduced and the effective utilization rate of the etherifying agent is reduced, which is economically disadvantageous. When (A1-A2) /E≧1.00, a part of carboxymethyl groups of CMC becomes an acid type by neutralization, and further, thermal crosslinking is performed in the drying step to reduce transparency and salt water resistance of the CMC aqueous solution or to perform thermal crosslinking. If the drying conditions are made mild enough to suppress the drying, the drying time is delayed and the productivity is lowered.

In the present invention, the most preferable weight ratio of the water-containing organic solvent to the organic solvent and water is 85:15 to 93:
7 range. Further, regarding the amounts of the alkali and the etherifying agent used in the present invention, the relational expression (1) is 0.92 to 0.
Optimally in the range of 98.

The present invention can be applied regardless of the method of adding an alkali or an etherifying agent. Therefore, a method of adding the entire amount of the used alkali before the addition of the etherifying agent, a method of dividing the used alkali before and after the addition of the etherifying agent, or a method of adding the entire amount of the used alkali after the addition of the etherifying agent Furthermore, it can be suitably applied to any addition method such as a method of simultaneously adding the total amount of the alkali used and the etherifying agent.

In the present invention, neutralization with an acid such as acetic acid is not required, and after removing the by-products such as salt by purifying the CMC after completion of the reaction with hydrous methyl alcohol which is widely used in the production of CMC. , Just dry.
Since the CMC after completion of the reaction of the present invention shows alkalinity, there is no problem in adjusting the pH using an extremely small amount of acetic acid or the like.

As described above, according to the present invention, the molar ratio of the alkali to the etherifying agent, which has been considered to significantly decrease the solubility of the produced CMC in the prior art [total mole number of used alkali A1, etherifying agent Even if the mole ratio of the alkali consumed for neutralization is A2 and the mole ratio of the etherifying agent used is E, the molar ratio = (A1-A2) / E] is less than 1.00. It is a technique that can be achieved only by combining a different molar ratio with a weight ratio of a specific organic solvent and water.

The methods for measuring and evaluating the quality of CMC and the effective utilization rate of the etherifying agent used in the present invention are as follows.

(1) DS (degree of substitution) 1.0 g of CMC (anhydrous) is precisely weighed and placed in a platinum dish to prepare 5
Ashing at 50-600 ° C., titration of sodium oxide generated by the incineration with 0.1 N sulfuric acid using phenolphthalein as an indicator, and calculating its titer Aml by the following formula, DS
Calculate (mol / c ₆ ). DS = {162 × A × f} / {10000-80 × A ×
f｝ (where f is the titer of 0.1N sulfuric acid)

(2) Viscosity 10 g of CMC (anhydrous) was precisely weighed, put in a 1000 ml beaker, added with 990 g of pure water, stirred and dissolved using a triangle stirring bar to adjust the liquid temperature to 25 ± 0.2 ° C. Then, using a BM type viscometer (manufactured by Tokyo Keiki Co., Ltd.), the rotation speed is 30r.
Read the viscosity after spinning for 3 minutes at pm.

(3) Transparency The transparency of the CMC 1% aqueous solution under a constant light source is controlled by the tube bottom φ30.
The transparency is expressed by the height of the liquid column in mm. The larger the transparency value, the better.

(4) Salt water resistance CMC (anhydrous) 10 g was precisely weighed, put in a 1000 ml beaker, added 990 g of 4% saline solution, stirred by using a triangle stir bar, dissolved, and liquid at 25 ± 0.2 ° C. After adjusting the temperature, a BM type viscometer (manufactured by Tokyo Keiki Co., Ltd.) is used to read the viscosity after rotating at a rotation speed of 30 rpm for 3 minutes. The salt water resistance is calculated from the following equation using the numerical value of the viscosity (1). The salt water resistance was evaluated to be more excellent as the value was larger. Salt water resistance = (CMC 1% viscosity in 4% saline) / (CMC 1% viscosity in pure water)

(5) Effective Utilization Rate of Etherifying Agent Using the number of moles of the etherifying agent used per glucose unit (mol / c ₆ ) and DS (mol / c ₆ ),
It is obtained from the following equation. Effective utilization rate of etherification agent (%) = (DS / number of moles of etherification agent) x 100%

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be shown below by examples, but the present invention is not limited to these examples.

[0029]

【Example】

Example 1 1604 g of IPA and 139 g of methyl alcohol were charged into a biaxial kneader having a volume of 5 L. Next, a solution prepared by dissolving 125.2 g of sodium hydroxide in 178 g of water was added.
Linter pulp with 7% water content (Brand name: Buckeye HVE, Buckeye Cellulous Corporat while keeping the temperature at 30 ℃)
215 g). While maintaining this temperature 6
Stir and mix for 0 minutes. Then, monochloroacetic acid 15
A solution prepared by dissolving 1.7 g in a mixed solution of 214 g of IPA and 22 g of water was added, and the mixture was stirred and mixed for 30 minutes, and then heated to 70 ° C. and maintained at this temperature for 60 minutes. Then, after cooling, the reaction product was purified twice with 10 L of 65% methyl alcohol and deliquored, and then at 90 ° C. for 1 hour and 140 ° C. with a blow dryer (model: SPS-12, manufactured by Tabai Espec Co., Ltd.). After drying for 1 hour, two types of CMC under different drying conditions were obtained.

Example 2 1515 g of IPA and 132 g of methyl alcohol were added to a biaxial kneader having a volume of 5 L. Next, a solution prepared by dissolving 119.7 g of sodium hydroxide in 153 g of water was added.
Linter pulp with 7% water content (Brand name: Buckeye HVE, Buckeye Cellulous Corporat while keeping the temperature at 30 ℃)
215 g). While maintaining this temperature 6
After stirring and mixing for 0 minutes, a solution prepared by dissolving 262.5 g of monochloroacetic acid in a mixed solution of 373 g of IPA and 35 g of water was added, and further stirred and mixed for 60 minutes. Then, 97.0 g of sodium hydroxide was added in a solid state, stirred for 60 minutes, mixed, and then heated to 70 ° C. and kept at this temperature for 60 minutes. After cooling, the reaction product was purified twice with 13 L of 75% methyl alcohol and deliquored, and then 9 with a blast dryer (model: SPS-12, manufactured by Tabai Espec Co., Ltd.).
It was dried at 0 ° C. for 1 hour and at 140 ° C. for 1 hour to obtain two types of CMC under different drying conditions.

Example 3 803 g of IPA and 70 g of methyl alcohol were put into a biaxial kneader having a capacity of 5 L. Then, sodium hydroxide 7
What melt | dissolved 7.1 in 119 g of water was thrown in. Wood pulp with 7% water content (trade name: N
-DPS, manufactured by Nippon Paper Industries Co., Ltd.). While maintaining this temperature, the mixture was stirred and mixed for 60 minutes. Then, a solution prepared by dissolving 93.3 g of monochloroacetic acid in a mixed solution of 128 g of IPA and 17 g of water was added, and the mixture was stirred and mixed for 30 minutes, then heated to 70 ° C. and kept at this temperature for 60 minutes. After cooling, the reaction was cooled to 2 with 10 L of 65% methyl alcohol.
After purification twice and deliquoring, blow dryer (model: SPS-1
2, manufactured by Tabai Espec Co., Ltd.) at 90 ° C. for 1 hour and 140 ° C. for 1 hour, respectively, to obtain two types of CMC under different drying conditions.

Comparative Example 1 1604 g of IPA and 139 g of methyl alcohol were put into a biaxial kneader having a capacity of 5 L. Next, a solution prepared by dissolving 134.0 g of sodium hydroxide in 178 g of water was added.
Linter pulp with 7% water content (Brand name: Buckeye HVE, Buckeye Cellulous Corporat while keeping the temperature at 30 ℃)
215 g). While maintaining this temperature 6
Stir and mix for 0 minutes. Then, monochloroacetic acid 15
A solution prepared by dissolving 1.7 g in a mixed solution of 214 g of IPA and 22 g of water was added, and the mixture was stirred and mixed for 30 minutes, and then heated to 70 ° C. and maintained at this temperature for 60 minutes. After cooling, the reaction product was neutralized with acetic acid, purified twice with 10 L of 65% methyl alcohol, and deliquored. Then, a blow dryer (model: SPS-
12, manufactured by Tabai Espec Co., Ltd.) at 90 ° C. for 1 hour and at 140 ° C. for 1 hour, respectively.
A type of CMC was obtained.

Comparative Example 2 1604 g of IPA and 139 g of methyl alcohol were charged into a biaxial kneader having a volume of 5 L. Next, a solution prepared by dissolving 117.5 g of sodium hydroxide in 178 g of water was added.
Linter pulp with 7% water content (Brand name: Buckeye HVE, Buckeye Cellulous Corporat while keeping the temperature at 30 ℃)
215 g). While maintaining this temperature 6
Stir and mix for 0 minutes. Then, monochloroacetic acid 15
A solution prepared by dissolving 1.7 g in a mixed solution of 214 g of IPA and 22 g of water was added, and the mixture was stirred and mixed for 30 minutes, and then heated to 70 ° C. and maintained at this temperature for 60 minutes. Then, after cooling, the reaction product was purified twice with 10 L of 65% methyl alcohol and deliquored, and then at 90 ° C. for 1 hour and 140 ° C. in a blow dryer (model: SPS-12, manufactured by Tabai Espec Co., Ltd.). After drying for 1 hour, two types of CMC under different drying conditions were obtained.

Comparative Example 3 618 g of IPA and 54 g of methyl alcohol were charged into a biaxial kneader having a capacity of 5 L. Then, sodium hydroxide 12
What melt | dissolved 5.2 in 178 g of water was thrown in. Linter pulp with 7% water content while keeping the temperature at 30 ℃ (Brand name: Buckeye HVE, Buckeye Cellulous Corporation
215 g). While maintaining this temperature, the mixture was stirred and mixed for 60 minutes. Then monochloroacetic acid 151.7
What was dissolved in a mixed solution of 214 g of IPA and 22 g of water was added, and after stirring and mixing for 30 minutes, the temperature was raised to 70 ° C. and this temperature was maintained for 60 minutes. After cooling, the reactants were
The product was purified twice with 10 L of 5% methyl alcohol, deliquored, and then dried by a blow dryer (model: SPS-12, manufactured by Tabai Espec Co., Ltd.) at 90 ° C. for 1 hour and 140 ° C. for 1 hour, respectively. Two types of CMC under different conditions were obtained.

Comparative Example 4 2576 g of IPA and 224 g of methyl alcohol were charged into a biaxial kneader having a capacity of 5 L. Next, a solution prepared by dissolving 125.2 of sodium hydroxide in 178 g of water was added. Linter pulp with 7% water content (Buckeye HVE, Buckeye Cellulous Corporation while keeping the temperature at 30 ℃)
215 g). While maintaining this temperature, the mixture was stirred and mixed for 60 minutes. Then monochloroacetic acid 151.7
What was dissolved in a mixed solution of 214 g of IPA and 22 g of water was added, and after stirring and mixing for 30 minutes, the temperature was raised to 70 ° C. and this temperature was maintained for 60 minutes. After cooling, the reactants were
The product was purified twice with 10 L of 5% methyl alcohol, deliquored, and then dried by a blow dryer (model: SPS-12, manufactured by Tabai Espec Co., Ltd.) at 90 ° C. for 1 hour and 140 ° C. for 1 hour, respectively. Two types of CMC under different conditions were obtained.

Comparative Example 5 1700 g of IPA and 148 g of methyl alcohol were charged into a biaxial kneader having a capacity of 5 L. Next, a solution prepared by dissolving 134.1 g of sodium hydroxide in 172 g of water was added.
Linter pulp with 7% water content (Brand name: Buckeye HVE, Buckeye Cellulous Corporat while keeping the temperature at 30 ℃)
215 g). While maintaining this temperature 6
After stirring and mixing for 0 minutes, a solution prepared by dissolving 262.5 g of monochloroacetic acid in a mixed solution of 373 g of IPA and 35 g of water was added, and further stirred and mixed for 60 minutes. Then, 97.0 g of sodium hydroxide was added in a solid state, stirred for 60 minutes, mixed, and then heated to 70 ° C. and kept at this temperature for 60 minutes. After cooling, the reaction product was purified twice with 13 L of 75% methyl alcohol and deliquored, and then 9 with a blast dryer (model: SPS-12, manufactured by Tabai Espec Co., Ltd.).
It was dried at 0 ° C. for 1 hour and at 140 ° C. for 1 hour to obtain two types of CMC under different drying conditions.

Comparative Example 6 857 g of IPA and 74 g of methyl alcohol were put into a biaxial kneader having a capacity of 5 L. Then, sodium hydroxide 8
What melt | dissolved 2.1 g in 127 g of water was thrown in. Wood pulp with a water content of 7% (trade name:
215 g of N-DPS, manufactured by Nippon Paper Industries Co., Ltd. was charged. While maintaining this temperature, the mixture was stirred and mixed for 60 minutes. Next, a solution prepared by dissolving 93.1 g of monochloroacetic acid in a mixed solution of 128 g of IPA and 17 g of water was added, stirred and mixed for 30 minutes, and then heated to 70 ° C. and kept at this temperature for 60 minutes. After cooling, the reaction product is neutralized with acetic acid, purified twice with 10 L of 65% methyl alcohol, and deliquored. Then, a blast dryer (model: SPS-12, manufactured by Tabai Espec Corporation).
Were dried at 90 ° C. for 1 hour and 140 ° C. for 1 hour to obtain two types of CMC under different drying conditions.

Table 1 shows the quality of CMC obtained from the reaction conditions of Examples 1 to 3 and Comparative Examples 1 to 6 described above. Examples 1 to 3 are CMCs obtained according to the manufacturing method of the present invention. Regardless of the drying temperature, the quality such as transparency and salt water resistance was excellent, and the effective utilization rate of the etherifying agent was also good.

On the other hand, in Comparative Examples 1, 5 and 6, the relational expression between the alkali and the etherifying agent, which is limited in the production method of the present invention, was not satisfied, and (A1-A2) / E was 1.00 or more. When the drying temperature was raised, the qualities such as transparency and salt water resistance were greatly inferior.

In Comparative Example 2, the relational expression between the alkali and the etherifying agent, which is limited in the production method of the present invention, is not satisfied (A1-
A2) / E was less than 0.85. Despite the drying temperature, the transparency was significantly poor and the effective utilization rate of the etherifying agent was also poor.

Comparative Example 3 does not satisfy the weight ratio of the solvent and water defined in the production method of the present invention, the solvent is less than 80% by weight and the water is 2%.
It was more than 0% by weight. Despite the drying temperature, the qualities such as transparency and salt water resistance were poor, and the effective utilization rate of the etherifying agent was also poor.

Comparative Example 4 did not satisfy the weight ratio of the solvent and water defined in the production method of the present invention. The solvent was more than 93% by weight and the water was less than 7% by weight. Despite the drying temperature, the qualities such as transparency and salt water resistance were poor.

[0043]

[Table 1]

[0044]

As described above in detail, according to the production method of the present invention, the CMC obtained by the conventional production method is excellent in the transparency and the salt water resistance even under the drying condition in which the quality such as the transparency and the salt water resistance is largely inferior. It turned out to be.

Therefore, in the conventional manufacturing method, it was necessary to lower the drying temperature to extend the drying time to such an extent that deterioration of quality such as transparency and salt water resistance can be suppressed, but this manufacturing method does not require it. It was found that industrial profits are large, such as productivity being greatly improved and contributing to reduction of the amount of sodium hydroxide and acetic acid used,
The present invention has been completed.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazutoshi Kinoshita 1280 Gotsu Town, Gotsu City, Shimane Prefecture Inside the Gotsu Mill of Nippon Paper Industries Co., Ltd.

Claims (3)

[Claims] 1. A hydrated organic compound in which a weight ratio of an organic solvent and water is 80:20 to 93: 7 in the production of an alkali salt of carboxymethyl cellulose ether obtained by etherifying a cellulosic raw material in a hydrated organic solvent. A carboxy characterized in that the total number of moles A1 of alkali used in the solvent and the number of moles A2 of alkali consumed for neutralizing the etherifying agent satisfy the following formula between the number of moles E of the etherifying agent used. Manufacturing method of methyl cellulose ether alkali salt. 0.85 ≦ (A1-A2) / E <1.00 (1) 2. The method for producing an alkali salt of carboxymethyl cellulose ether according to claim 1, wherein the value of the formula (1) is 0.92 to 0.98. 3. The weight ratio of organic solvent to water is 85:15.
93: 7, The method for producing an alkali salt of carboxymethyl cellulose ether according to claim 1 or 2.