JPS61157501A - Production of alkali metallic salt of carboxymethyl cellulose - Google Patents

Abstract

PURPOSE:To reacting a cellulosic raw material with an inorganic alkali metallic compound, to obtain the titled metallic salt useful as a thickening agent, a dispersant, protective colloid, etc., having improved salt water resistance, high degree of substitution, and high viscosity, by reacting the reaction mixture with epichlorohydrin. CONSTITUTION:When a cellulosic raw material (e.g., wood pulp, linter, etc.) with an inorganic alkali metallic compound (e.g., NaOH, etc.) in a hydrous organic solvent (e.g., ethanol, acetone, etc.), then reacted with an etherifying agent (e.g., monohalogenoacetic acid, etc.), or the cellulosic raw material is impregnated with the etherifying agent, then the inorganic alkali metallic compound to advance the reaction, epichlorohydrin is reacted with the reaction mixture while the cellulosic raw material is reacted with the inorganic alkali metallic compound or after the reaction is completed, to given the aimed metallic salt having >=0.80 deg. of carboxymethyl substitution.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a method for producing carboxymethylcellulose alkali metal salt (hereinafter abbreviated as CMC) which has excellent salt water resistance, high degree of substitution, and high viscosity. More specifically, when manufacturing CMC, epichlorohydrin is applied during the manufacturing process to achieve a high degree of substitution with excellent salt water resistance (by a carboxymethyl group per anhydroglucose, which is a constituent unit of cellulose). The present invention relates to the production of a carboxymethyl cellulose alkali metal salt having a high viscosity of 0.80 or more (average number of substituents (hereinafter abbreviated as DS)).

CMC is a cellulose ether produced by reacting monochloroacetic acid etc. with cellulose in the presence of an alkali.As a water-soluble polymer electrolyte, it is used as a thickener, dispersant, protective colloid agent, adhesive, and muddy water additive for petroleum poling. (b) Conventional techniques CMC production methods are broadly divided into two methods: an aqueous method that uses an aqueous medium as the reaction medium, and a solvent method that uses an organic solvent. Compared to the aqueous method, the solvent method can obtain alkali cellulose with a smaller amount of alkali, the etherification reaction is achieved in a relatively short time, the effective utilization rate of the etherification agent is high, and a small amount of etherification agent is required. It only requires the use of C, which has a high viscosity.
Since MC is easy to manufacture, it is widely used in industrial applications.Currently, commercially available CMCs are DBo, 4 to 1.7
0 and especially 0.6 to 0.80 are commercially available in large quantities. However, recently, the functions required for CMCK have become more sophisticated, and as a result, the amount of CMC used by DSO18 to DSO1.70 tends to increase. Furthermore, DSl, 70~2
．． 90 ultra-high DSCMCs are becoming commercially available.

This is because by increasing the DS of CMC, salt water resistance, acid resistance, spoilage resistance, fluidity, etc. are generally improved.

However, by increasing the DS of CMC, the amount of alkali used during CMC production increases, and therefore KC during the reaction
The degree of polymerization of MC was markedly reduced, and it was difficult to produce high-viscosity CMC.

For this reason, high DS and high viscosity CMC is often produced using linter, which generally has a higher degree of polymerization than wood pulp, as a raw material for cellulose. However, it is still sufficient to use linter as a raw material. High viscosity C
Not only is it impossible to obtain MC, but the reactivity is generally lower than that of wood pulp, and therefore, it may be difficult to obtain CMC that is satisfactory in terms of quality. Furthermore, linters are more expensive than wood pulp and are economically disadvantageous.

Furthermore, CMC has conventionally been used as a method for manufacturing high viscosity CMC.
A method is known in which epichlorohydrin is allowed to act on the θ-mass during the manufacturing process (Watanabe Koichi, Industrial Chemistry Magazine, Vol. 68, p. 1923,
(1965).

According to the above-mentioned literature, the mechanism of action of epichlorohydrin is thought to be that in the presence of an alkali, it reacts with the water groups of cellulose in the following manner to form a crosslinked structure, thereby increasing its viscosity.

-+Ce1l-0-CH2-CH-CH2C1+NaO
HH This report has attracted attention as a method for producing CMC with high viscosity during vortexing, and many attempts have been made to apply it. However, although it has a high viscosity, its resistance to salt water is extremely poor, so its industrial application has hardly been made. This was at that time (1965)
Most industrially manufactured CMCs have a DS of 0.50~
Since it had a low DSCMC of 0.70, it is thought that the CMC cross-linked with epichlorohydrin was hardly dissolved in water containing salt such as common salt because the dissociation of carboxyl groups was extremely suppressed.

(c) Purpose of the invention This invention was made under the above circumstances.
The object of the present invention is to provide an alkali metal salt of carboxymethyl cellulose that has a high viscosity, salt water resistance, and is easy to tow.

B) Structure of the Invention The present invention is characterized in that A) a cellulosic raw material is reacted with an inorganic alkali metal compound in a water-containing organic solvent, and then an etherification agent is reacted, or B) an etherification agent is added to the cellulosic raw material. and then add an inorganic alkali metal compound to allow the reaction to proceed, and during step B) or B), react with epichlorohydrin during or after the reaction with the inorganic alkali metal compound is completed. , carboxymethyl substitution degree 0.80
The present invention provides a method for producing a carboxymethylcellulose alkali metal salt having the above characteristics and excellent salt water resistance and high viscosity. 0.8
The above carboxymethylcellulose alkali metal salt is obtained.

The cellulosic raw material used in this invention is C
Those commonly used in MCll1 construction include wood valves or linters.

In this invention, the water-containing organic solvent used as a reaction medium includes ethyl alcohol, inpropyl alcohol (hereinafter abbreviated as IPA), n-propyl alcohol, tart-butyl alcohol, isobutyl alcohol, n-7'yl alcohol, Organic solvents such as acetone and dioxane, as well as ethyl alcohol-benzene,
Ether alcohol - toluene, ethyl alcohol - n-
Hexane, IPA-benzene, IPA-toluene and I
Examples include mixtures of mixed organic solvents such as PA-n-hexane, and water. The amount of the water-containing organic solvent used is usually 1 to 30 times the weight of the cellulosic raw material.

The inorganic alkali metal compound in this invention may be any compound that forms alkali cellulose.

Specific examples include sodium hydroxide, hydroxide
'C rubidium, cesium hydroxide, etc. However, there is no particular limitation to these. Sodium hydroxide is the most advantageous because it is inexpensive. Note that the CMC produced by the method of this invention becomes a salt of the alkali used.

Therefore, if sodium hydroxide is used, CMC becomes the sodium salt.

The etherification agent of this invention is a reagent capable of introducing a carboxymethyl group. Specific examples thereof include monochloroacetic acid, its alkali metal salts, or its ester derivatives such as methyl, ethyl or isopropyl esters.

In the method of this invention, at least alkali cellulose or m≠
This is done when at least one copy of CMC has been generated.

To produce alkali cellulose or hexagonal CMC, a cellulosic raw material is reacted with an inorganic alkali metal compound and then an etherification agent, or B) an etherification agent is reacted with the cellulosic raw material in a water-containing organic solvent. and then adding an inorganic alkali metal compound and reacting, or A)bB).

A) Method essentially involves reacting a cellulosic raw material with an inorganic alkali metal compound (hereinafter referred to as alkali) to form alkali cellulose, and then guiding this alkali cellulose from Chidaibu to CMC using an etherification agent. be.

At that time, the etherification agent may be reacted in a state where all of the cellulosic raw material is not converted into alkali cellulose, and the reaction may be further carried out by adding a required amount of alkali.

In method B), a cellulosic raw material is impregnated in advance with the entire required amount of etherification agent, and an alkali is added thereto to allow the reaction to proceed.

The amount of alkali used is the amount necessary to convert the cellulosic raw material into alkali cellulose.

On the other hand, in the present invention, it is desirable to adjust the molar ratio of alkali and etherification agent used in the etherification step. The alkali is added to the etherification agent in a molar ratio of 1.00 or more.

It is usually preferable to maintain a molar ratio of 1.00 to 1.30. Note that the molar ratio of the "alkali" to the "etherifying agent" is expressed as follows.

If the amount of alkali present in the reaction system is large, it will only promote the side reaction of sodium monochloroacetate, which is an etherification agent, as shown in the following formula, and reduce the effective utilization rate of the expensive etherification agent. This results in the inability to obtain the desired DS CMC.

CICHzCOONa+NaOH4CHz(OH)CO
ONa+NaC1 On the other hand, when trying to produce CMCt- with high DS by focusing on high functionality such as improving the salt water resistance of CMC, the amount of etherification agent charged will naturally increase, but this will inevitably result in the addition of alkali. Usage increases.

On the other hand, it is preferable that the etherification agent is present in excess at the beginning of the etherification step. Specifically, it is preferable that the alkali be present in a molar ratio of 0.10 to 0.99 to the etherifying agent. Then, in order to prevent the reaction system from becoming acidic due to the consumption of alkali as the etherification reaction progresses, it is desirable to further add alkali and carry out the etherification reaction, resulting in a final molar ratio of 1.00 or more. It will be done. This allows a relatively high CMC of DS to be obtained. This method of adjusting the amount of alkali added constitutes one of the features of the present invention.

When the DS is low, a method in which the alkali is present in excess of the etherifying agent, that is, in a molar ratio of 1.0 to 1.3 from the beginning, is sufficient. This has the advantage of simple operation and short reaction time.

In addition, since the amount of alkali used increases, the DS obtained in one reaction operation has an upper limit of 1.7 if the required amount of alkali is added from the beginning;
Approximately 2. ．． 2 is the upper limit.

DSl, 50 or more, especially high D of DS 1.80 or more
When obtaining the object of this invention having S, a high DS
It is preferable to prepare CMC in advance and react it with epichlorohydrin without isolating it. Such cases are also included in the method of the present invention.

Note that the step of preparing alkali cellulose by applying an alkali to the cellulosic raw material and the step of adding and mixing an etherifying agent such as monochloroacetic acid are performed by stirring and mixing at 10 to 40° C. for about 10 to 180 minutes. On the other hand, the etherification reaction is suitably carried out at 50 to 80°C for 30 to 240 minutes.

Next, in the method of the present invention, epichlorohydrin is added and reacted at the stage when at least alkali cellulose or CMC is produced from the cellulosic raw material.

Since the epichlorohydrin to be added is a liquid at room temperature, it may be added as is in small amounts, but it is preferable to dilute it with an organic solvent used as a reaction solvent and then add it.

As mentioned above, the action mechanism of epichlorohydrin is thought to be that it reacts with the water groups of cellulose or CMC in the presence of alkali and cross-links between or within molecules, so if the system is alkaline, it can be added at any time. Although it is possible to do this at the stage of the etherification reaction, considering the uniformity of crosslinking and the effective utilization rate of epichlorohydrin, it is necessary to prepare the alkali cellulose before the etherification reaction or in the presence of an alkali, where the amount of alkali in the system is large and the temperature is kept low. It is preferable to add the etherification agent to the bottom of the etherification agent prior to or during the step of adding and mixing it. Although it appears that the action takes place in a short period of time, it is preferable to keep the action for about 10 minutes or more.

The amount added varies depending on the type of cellulosic raw material used, the type and amount of reaction solvent used, the timing of addition of DS to CMe to be produced, etc., but it is 0.05 to 4.0% based on the weight of the cellulosic raw material. %, preferably 0.1~'
Add LOchi. That is, when it is less than 0.05, almost no thickening effect is observed, and when it exceeds 4%, it becomes partially water-insoluble.
Salt water resistance deteriorates.

By adopting the manufacturing method of this invention as described above,
This method not only has the advantage of being able to manufacture high DS and high viscosity CMC using inexpensive wood pulp as a raw material, but also previously could not be manufactured using linter as a raw material. It becomes possible to produce CMC with high DS and high viscosity. Furthermore, by appropriately adjusting the amount of epichlorohydrin added, it is possible to not only adjust the viscosity of the produced CMC but also its flow behavior. In other words, by increasing the amount of epichlorohydrin added and increasing the degree of crosslinking, high DSCMC had a flow behavior close to Newtonian flow.
It is possible to change the fluidity of an aqueous solution to a highly thixotropic fluidity.

From the above, the CM manufactured by the method of this invention
C is not only useful as a muddy water additive for petroleum poling or as a muddy water additive for civil engineering polling in the presence of seawater or salt water, but also in many other applications such as in the presence of salt such as common salt. Useful.

Examples and comparative examples specifically explaining the present invention will be shown below, but the present invention is not limited to these examples.

Note that the properties of the generated CMC are (1) degree of substitution (DS);
The measurement and evaluation methods for (2) viscosity, (3) salt water resistance, and (4) etherification agent effective utilization rate (AM) are as follows. (1) Degree of substitution (DS) Weigh it, put it in a platinum crucible or magnetic crucible, and incinerate it at 600°C. Titrate the sodium oxide produced by the ashing with N/1oH2S04 using phenolphthalein as an indicator, and enter the titration amount A- into the following formula. DS was obtained.

Here, f is the titer of N/1oH2S04.

(2) Viscosity measurement method CMC2,st was placed in a cylindrical glass container with a diameter of 55 and a depth of 125 mm, and pure water or 4% saline was added until the CMC was 1.
．． Pour and dissolve to a concentration of 0% (by weight). Next, after adjusting the temperature to 125℃, BL type viscometer (Tokyo Keiki ■
After rotating the rotor at 6 Orpm for 1 minute using a rotor (manufactured by Mikuni, Ltd.), the numerical values were read and multiplied by a predetermined constant to determine the viscosity. The unit is CP (centipoise).

(3) Salt water resistance Salt water resistance was evaluated based on the viscosity ratio determined by the following equation.

It was evaluated that the higher the viscosity ratio, the better the salt water resistance.

(4) Etherification agent effective utilization rate (AM) was calculated using the following formula.

Number of moles of anhydroglucose units In Examples and Comparative Examples, parts are parts by weight, and parts by weight are % by weight.
shows.

(F) Examples (Example 1) In a 5 t Unilunar type kneader with two-shaft stirring blades, 760 parts of Inglobil alcohol (hereinafter abbreviated as IPA) and hydroxide) IJium (purity 98.0%) ) was added by dissolving 140.0 parts of pure water, cooled to 10 to 15° C. by passing cold water through the jacket, and purged with nitrogen gas several times to remove air.

Next, powdered wood pulp 2 with a moisture content of 6% and a degree of polymerization of 750
After adding 00 parts of the mixture, nitrogen gas is purged several times to remove air, and the mixture is stirred and mixed at 12 to 20°C for 120 minutes to prepare alkali cellulose.

During the preparation of the alkali cellulose (after 60 minutes), 1.0 part of epichlorohydrin was dissolved in 100 parts of IPA and added.

Next, monochloroacetic acid 162.4 f (purity 98.5
%) in IPA 162.4f and add it little by little.
Stir and mix at 5-25°C for 30 minutes, then heat water through the jacket to raise the temperature to 70°C, and heat at 70°C for 12 minutes.
The etherification reaction is carried out for 0 minutes. Excess sodium hydroxide is then neutralized with acetic acid and cooled to room temperature by passing cold water through the jacket.

Next, the kneader-washed reaction mixture is removed and centrifuged to remove the IPA aqueous solution. Next, the product was washed three times with 4 tons of 75-thimethyl alcohol aqueous solution to remove by-products such as salt, and then dried at 80-110°C for 4 hours.
The results are summarized in Table 1.

<Examples 2 to 5 and Comparative Examples 1 to 4> Example 2 was carried out under exactly the same conditions and method as in Example 1, except that the amounts of sodium hydroxide and monochloroacetic acid used and the amount of epichlorohydrin added were different. and 5 and Comparative Examples 1 to 4. The results are summarized in Table 1.

〈Example 6〉 A 5-ton Uniluna-Huang Nigu with two-shaft stirring blades,
Add 675.1 parts of IPA and add 1 part of sodium hydroxide.
Dissolve 58.0 parts (purity 98%) in 158.0 parts of pure water and cool to 12-20°C, water content 6%, degree of polymerization 75
200 parts of powdered wood pulp of 0.0% was added, and the air was removed by purging with nitrogen gas several times.
Mix and stir for 0 minutes to prepare alkali cellulose. During the preparation of this alkali cellulose (after 60 minutes), 1.0 part of epichlorohydrin was dissolved in 100 parts of IPA and added. Next, 244.9 parts of monochloroacetic acid (purity 9
8%) was dissolved in 244.9 parts of IPA, added while cooling, and stirred and mixed at 12 to 25°C for 30 minutes. Thereafter, the temperature was raised to 60° C. in about 10 minutes, and the etherification reaction was carried out for 60 minutes. Next, add 54.3 parts of sodium hydroxide to 3 parts of pure water.
The mixture was dissolved in 6.2 parts and added, stirred and mixed at 60 to 70°C for 15 minutes, and then heated to 70°C and subjected to an etherification reaction for 90 minutes. Thereafter, the slight remaining sodium hydroxide is neutralized with acetic acid.

The subsequent operations were carried out under exactly the same conditions and method as in Example 1 to obtain CMC of the present invention. The results are summarized in Table 1.

<Example 7> In place of the powdered wood pulp of Example 6, DSL, 54 pure water Is viscosity 1i 340 cp moisture 71 M [99 ts powdered CMC 359.4 parts (188.0 parts in terms of cellulose)
CMC of the present invention was obtained under the same conditions and method as in Example 6, except that 0 was used.The results are summarized in Table 1.

Comparative Examples 5 and 6 Comparative Example 5 was carried out using the same method and conditions as Example 6, but no epichlorohydrin was added, and Comparative Example 5 was carried out using the same conditions and method as Example 7, but no epichlorohydrin was added. This was referred to as Comparative Example 6. those results first
It is summarized in the table.

Comparative Example 7> The same conditions as in Example 6 were used except that 200 parts of linter (moisture: 61, degree of polymerization: 2,100) was used instead of the powdered wood powder of Example 6, and epichlorohydrin was not added. The results were summarized in Table 1.As is clear from Table 1, the CMC of the example manufactured by the manufacturing method of this invention was manufactured by the conventional method. Compared to CMC, it has a much higher viscosity and excellent salt water resistance.

Claims (1)

[Claims] 1. A) reacting an inorganic alkali metal compound with a cellulosic raw material in a water-containing organic solvent, and then reacting an etherifying agent, or B) adding an etherifying agent to the cellulosic raw material. impregnation, then adding an inorganic alkali metal compound to allow the reaction to proceed; during this step A) or B), during or after the reaction with the inorganic alkali metal compound, epichlorohydrin is reacted to form carboxymethyl Substitution degree 0.80
A method for producing a carboxymethyl cellulose alkali metal salt, which is characterized by obtaining the carboxymethyl cellulose alkali metal salt having the above properties, excellent salt water resistance, and high viscosity. 2. The inorganic alkali metal compound is initially added to the etherification agent at a molar ratio of 0.10 to 0.99, and then added at a molar ratio of 1.00 or more to the etherification agent to initiate the reaction. The manufacturing method according to claim 1, characterized in that the manufacturing method is allowed to proceed. 3. The manufacturing method according to claim 1 or 2, wherein the cellulosic raw material is wood pulp or linter. 4. The production method according to any one of claims 1 to 3, wherein the etherification agent is monohalogenoacetic acid, or an alkali metal salt or lower alkyl ester thereof. 5. The production method according to any one of claims 1 to 4, wherein the inorganic alkali metal compound is sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, or cesium hydroxide. 6. A mixture of water and an organic solvent in which the water-containing organic solvent is ethanol, n-propanol, isopropanol, n-butanol, t-butanol, isobutanol, acetone, dioxane, benzene, toluene, or n-hexane, or a mixture thereof. The first claim is
The manufacturing method according to any one of items 1 to 5. 7. According to any one of claims 1 to 6, the intermediate carboxymethylcellulose alkali metal salt produced after reacting the etherification agent has a degree of carboxymethyl group substitution of 1.00 or more. manufacturing method. 8. The production method according to any one of claims 1 to 7, wherein the target carboxymethyl cellulose alkali metal salt has a carboxymethyl group substitution degree of 0.80 to 3.0.