JPS6044502A - Cellulose derivative and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention @) Technical Field The present invention relates to a cellulose derivative containing a carboxyethyl group and a carbamoylethyl group and a method for producing the same.

←) Prior Art Conventionally, the industrial method for producing molded products such as cellulose fibers and films is to dissolve cellulose in a cupric ammonia solution or xanthate it to form a solution, which is then coagulated using an acid or alkali. A method of regenerating the material is being adopted. However, these industrial methods consume large amounts of water;
It includes many points that require improvement, such as the need to recover heavy metals and high energy consumption.

In recent years, in order to eliminate such drawbacks and to close the process, a method has been proposed in which cellulose is dissolved in an organic solvent and the resulting dope is directly spun and shaped. However, in actual applications, it is necessary to use two or more solvents together, including the N-methylmorpholine N-oxide system, which has attracted attention in recent years, and the trimethylsulfoxide/paraformaldehyde system. Therefore, it has been found that there are fatal drawbacks in terms of workability and solvent recovery, such as a complicated method for recovering and reusing the solvent.

Despite the various drawbacks mentioned above, cellulose has good reproducibility, low cost, and abundant functionality, so it is well worth reconsidering. When combined with specific solvents, liquid crystals are formed, and the molded products obtained from this are expected to have significantly improved mechanical properties.

Purpose of the Invention As a result of comprehensively examining the shortcomings of the prior art and new possibilities as described above, the present inventors have found that the present inventors have developed a method that is soluble in inexpensive solvents and that is optically soluble in combination with specific solvents. We have discovered a new cellulose derivative that provides ion-exchange fJf: and mold resistance, and has achieved the present invention.

That is, an object of the present invention is to provide a novel cellulose derivative that is soluble in inexpensive solvents such as water and aqueous alkaline solutions, and that provides dough with excellent moldability (for example, molding into fibers). .

B) Structure of the Invention The cellulose derivative according to the present invention contains only a carboxyethyl group and a carbamoylethyl group as substituents, and the respective degrees of substitution are 0.1 to 0.7 and 0.05 to 0.8.
5, which is characterized by a total degree of substitution of 0.15 to 1.55.

The method for producing the above-mentioned cellulose derivative according to the present invention involves immersing cellulose in an alkaline aqueous solution having a concentration of 8 to 35M and then squeezing the cellulose to adjust the weight ratio of cellulose/alkaline aqueous solution to l10.
i3 to 115.0, add 10.5 to 10.0 moles of acrylonitrile to this, and stir at a temperature of O to 80°C for 5 to 120 minutes,
Thereafter, water or aqueous alkaline solution is added so that the raw material cellulose is 20 to 30% by weight, stirred and aged for 1 to 18 hours to obtain a homogeneous solution, and then either precipitated with a precipitant after neutralization, or precipitated with a precipitant after precipitation. It is characterized by being harmonious.

(E) Embodiment Conventionally, many methods have been known for reacting cellulose with acrylonitrile using an alkali catalyst as a cyanoethylation reaction of cellulose. These methods are
All have in common that acrylonitrile reacts with water to produce β,β'-dioxypropionitrile as a side reaction product, so the reaction is carried out in a system that contains as little water as possible. In this reaction, a suitable weight ratio of cellulose and aqueous alkaline solution is 1:3 to 1:0.8. On the other hand, in this reaction, the alkaline concentration is important, and there are literatures and patents stating that when the concentration is less than 10%, cyanoethylcellulose is mainly obtained, and when it is more than 15%, carboxyethylcellulose is mainly obtained. Reaction temperature is also an important factor. When 0.2 to 0.5 mol of acrylonitrile per glucose residue of cellulose is reacted with 20 to 30% alkali at a temperature of 5 to 35°C, water-insoluble, alkali-soluble caldexethel cellulose is obtained. It is said. However, Arca January 7
．． ': As the temperature increases by 4 degrees, the reaction becomes more complicated, and carboxydal ethylation occurs through cyanoethylation of the cell mouth, decyanoethylation, carbamoyl of cyanethylated cellulose, and de14 of the converted side chains. The exchange reaction also proceeds at the same time. So far, cellulose has been reacted with acrylonitrile using an alkaline catalyst, alkali-soluble cyanethylcellulose, and water-soluble cyanethylcellulose. There are only a few known examples of obtaining xylether cellulose.

Even in that case, there is a drawback that a large amount of unreacted cellulose remains. And, the carbamoyl ether-cal? according to the present invention. There are no reports of xyethylcellulose containing 47'C. This is thought to be because the above-mentioned complex reactions are all competitive reactions, making it difficult to find conditions for producing the cellulose derivative according to the present invention.

The cellulose derivative of the present invention with excellent moldability has a degree of substitution of 0.05. Contains only carbamoylether groups of ~0.85 and carboxyethyl groups with a degree of substitution of 0.1 to 0.7 as substituents, and has a total degree of substitution of 0.15 to 1.55.
It is a cellulose derivative that is soluble in aqueous alkaline solutions and water. As mentioned above, this derivative is a reaction product of alkali cellulose and acrylonitrile, and although it has been theoretically possible to produce it in the past, no examples have been found in which such a derivative has actually been successfully produced.

The degree of substitution of carboxyethyl groups and carbamoylethyl groups in the present invention is measured by the following method. The N content of the well-washed and dehydrated sangur is weighed using a CHN measuring device, converted to 1 CH2CH2CONH2 (carbamoyl group) contained in the sangur, and its weight % (5) is calculated. The -CH2Qj2CQ9Np (carboxy ether) group in the sanguru is converted into acid form and neutralized.

-CH2, CH2CC00N and its weight % (
B) You can make a claim. Letting the degree of substitution of the carboxyl group be x- and the degree of substitution of the carbamoyl group be y, x and y are the following simultaneous equation 1 formula % On the other hand, the weight fractions of -CH2CH2CONH2 and -CH2CH2COOINa of various samples were measured, and each A film of the sample was prepared, and IR measurement was performed to determine the absorbance based on 1CH2Ci (2CONH2) of the remaining OH group (3500yn-') in the sample.
cm ) and absorption based on -CH2CH2COONm (
Calculate the absorbance of 1560t;'). By plotting each absorbance against the weight fraction obtained as described above and creating a calibration curve, the above substitution degree of any sample can be determined.◎ The degree of carboxyethyl group substitution according to the present invention is 0.1 to 0. .7
．． One of the characteristics of cellulose derivatives having a carbamoylethyl group substitution degree of 0.05 to 0.85 and a total substitution degree of 0.15 to 1.55 is that a carboxyethyl group and a carbamoyl group can be separated depending on the value of the total substitution degree. The ratio of the degree of substitution (A mocargoxy ether group/carbamoylether group) changes, and the solubility changes accordingly! Generally, the value of A above is about 1.0 to 0.8 when the total degree of substitution is between LO and 1.55.
However, when the total degree of substitution is 1.0 or less, the value of A is approximately 1.0 ~
It is 8.0. This person's value tends to increase as the total substitution degree decreases.

Generally, if the total degree of substitution is less than 0.15, it will not be dissolved in a high concentration in a simple welding solution such as an alkaline aqueous solution at room temperature, making it difficult to produce a dough suitable for molding.

Furthermore, it is difficult to produce cellulose derivatives with a degree of substitution exceeding 1.55 by the method of the present invention. In the cellulose derivative of the present invention, the degree of substitution (DS) is 0.15 to
0.29 is soluble in dilute alkaline aqueous solution. DS
When it is 0.3 or more, it is soluble in water, and when it is 0.7 or more, it is also soluble in organic solvents with a large dielectric constant.

The carboxyethyl group imparts an interaction effect with cations to the product obtained by molding the cellulose derivative. On the other hand, the carbamoyl ether group gives the load-bearing conductor excellent anti-fungal properties.

Incidentally, both the carbamoylethyl and calxyether substituents are reactive substituents, and it is also possible to chemically change the substituents with various reactants. Moreover, this cellulose derivative can also be easily crosslinked.

Cellulose derivatives having the general characteristics as described above are
It can be manufactured by the method of the present invention as described above. The gist of this production method is to react cellulose with acrylonitrile under an alkali catalyst so that no cyanoethyl groups remain.
Moreover, the purpose is to efficiently produce cellulose derivatives containing carboxyethyl groups and carbamoyl ether groups, and the main point in the production process is to add water to an appropriate concentration after reacting with acrylonitrile. In addition, it has to be matured.

The cellulose raw material used in the present invention may be natural cellulose such as cotton or wood (which may contain impurities such as lignin), or may be regenerated cellulose. Natural cellulose containing impurities such as lignin is processed after derivative preparation.
By preparing Dogue with a suitable solvent and filtering it, impurities can be easily removed together with undissolved substances. The number average degree of polymerization of the raw material can be adjusted by depolymerizing with acid or alkali depending on the purpose. Usually, the degree of polymerization of the raw materials should be 100 or more. Furthermore, in order to improve the mechanical properties of the product, those having a degree of polymerization of 1,000 or more can be used.

The alkaline concentration when immersing cellulose in an alkaline aqueous solution is important and ranges from 8 to 351%.

If the amount is less than 8% by weight, the product will contain cyanoethyl groups, and if it exceeds 35% by weight, the reaction will not proceed smoothly and a large amount of unreacted cellulose will remain. This phenomenon naturally depends on the amount of acrylonitrile added, which will be described later. When cellulose is immersed in the above alkaline aqueous solution, the larger the alkali aqueous solution is in excess of the cellulose, the more alcelization will progress;
~10 times the amount is appropriate. The lower the degree of cellulose, the less this aqueous alkali phase is required.

The temperature during dipping is set at 0 to 60° C., since cellulose will cause a catalytic polymerization reaction if the temperature is too high. Soaking time is 5~
10 minutes is sufficient; however, cellulose can be activated with alkali within a shorter period of time as long as it is stirred.

Squeezing after immersion in the alkaline aqueous solution is an important factor, and the amount of the alkali solution is 0.8 to 5 times the weight of the cellulose. Squeezing is performed by mechanical methods such as presses and rollers. A reduction of less than 0.8 times is mechanically disadvantageous.

On the other hand, if it exceeds 5.0 times, side reactions of acrylonitrile will be promoted, which is not preferable. In particular, in order to reduce side reactions of acrylonitrile during the initial reaction between acrylonitrile and cellulose, the alkali solution should be adjusted to a concentration of 0.8 to 1.
It is desirable that it be five times as large.

The alkali-containing liquid cellulose thus obtained (hereinafter abbreviated as "alkali cellulose") is transferred to a reactor such as a kneader, the reaction system is heated to 0 to 80°C, and acrylonitrile is added to the alkali cellulose in liquid or gaseous form to react with the cellulose. Add 90.5 to 10 moles per glucose residue. During the addition of acrylonitrile, it is preferable that the alkali cellulose be in a stirred state from the viewpoint of uniformity of the reaction. Cyanoethylation of cellulose is rapid, and in such a highly alkaline state, carbamoylation and decyanoethylation of cyanoethyl groups proceed simultaneously. The amount of acrylonitrile (IJ) added is determined in correlation with the timing of adding water or aqueous alkaline solution to the reaction system and the reaction temperature.

The amount of acrylonitrile added is basically 9% per glucose residue.
A 0.5M vortex does not give a derivative (DS≧0.15) that easily dissolves in alkali at high concentrations. When the amount of acrylonitrile exceeds 10 moles, it is easy to obtain a derivative that forms the useful compound of the present invention, but from the viewpoint of self-polymerization of acrylonitrile, side reactions, etc., the addition amount exceeding 10 moles has little meaning and is not economical. It is also disadvantageous. Derivatives of the present invention t-
When producing a membrane, the amount of acrylonitrile added is preferably υ0.5 to 3.5 moles per glucose residue, considering the initial reaction efficiency and economic efficiency between cellulose and acrylonitrile.

The most important feature of the production method according to the present invention is that water or aqueous alkali solution is added to the reaction system at the point when the carbamoylation of cellulose reaches its maximum, and the carbamoyl group is carboxyethylated slowly in a homogeneous reaction system. . The initial reaction temperature and time between cellulose and acrylonitrile are set to maximize carbamoylation. Such temperature and time can be selected within the range of 0 to 80°C and 5 to 120 minutes.

Generally, the maximum point of carno-tetramoylation of cellulose (time until the degree of carbamoyl substitution reaches the maximum) is 10 to 40 minutes after addition of acrylonitrile.

The higher the temperature is between 5 and 40°C, the faster the maximum point will be.1 If the amount of acronitrile added is small, for example, when the amount of acronitrile is about 0.5% per glucose residue, a reaction temperature of 5 to 35°C is appropriate. ,
It is preferable to add water or an alkali after 30 to 40 minutes. Also, the amount of acrylonitrile is large, for example 0.7 to 1.
In the case of 0 mol, water or alkaline aqueous solution is added within 5 to 15 minutes when the reaction temperature is 30 to 40℃, and the reaction temperature is 5 to 40℃.
When the temperature is around 25°C, it is desirable to add water or aqueous alkaline solution within 15 to 40 minutes. In this way, water or alkali is added to the system to perform so-called ripening. If the reaction is stopped at the maximum point, for example by neutralization, the resulting product will be complex and will not dissolve uniformly in alkali or water.

Aging in water or alkali seems to be important in terms of rearrangement of substituents. In addition, if the initial reaction time is long, the desubstitution becomes a heterogeneous reaction, resulting in a disadvantage that a large amount of unreacted cellulose remains. The amount of water or alkaline aqueous solution added is such that the concentration of the cellulose raw material is 20 to 30M. Furthermore, if 3 to 15% by weight aqueous alkaline solution is added, this aging can be shortened and the degree of carboxyether substitution can be improved.

When the degree of polymerization of the cellulose raw material is low, a relatively small amount of water is sufficient. If a large amount of water is added, the subsequent ripening step will take a long time and the cost of product separation will increase. Aging after hydrogenation is important and requires 1 to 18
By holding for a period of time, it is possible to obtain the cellulose derivative of the present invention having only a sodium salt of a carboxyethyl group containing a cyanethyl group as a substituent and a carbamoylether group. Generally ripening is a function of temperature and the concentration of alkali added. In the case of water addition, for example, it takes 3 to 10 hours at 30°C, and 10 to 18 hours at 10°C or lower. Further, for example, when 10 weight of alkaline liquid is added, aging at 30° C. usually takes less than 3 hours. If the initial reaction and ripening steps are carried out under reduced pressure, the ripening time is generally set back.

After ripening, the alkaline solution can be used as it is or after neutralization to form dough 1 for molding, for example, fibers, hollow fibers, moons, etc. Alternatively, it can be precipitated with a precipitating agent such as methanol or acetone, and then washed with water or neutralized with an acid, or it can be precipitated with a precipitating agent after adding a neutralizing agent such as an acid to the aging liquid.

The obtained cellulose derivative of the present invention generally has 2 to 3
5 weight multi-concentration alkaline aqueous solution, water, Schweitzer's reagent, rust-thick inorganic salt aqueous solution (for example, lithium chloride D thick solution, calcium thiocyanate concentrate, zinc chloride concentrate),
Soluble in concentrated inorganic acids, trifluoroacetic acid, aqueous monochloroacetic acid and commonly known cellulose solvents. Furthermore, those with a high degree of substitution, such as a total degree of substitution of 0.6 or more, are soluble in amides such as formamide and dimethylacetamide, specific solvents such as orthochlorophenol, and mixtures of water and organic solvents.

(f) Effects of the Invention The cellulose derivative according to the present invention is generally soluble in simple solvents such as water and alkaline water baths, and can be easily formed into fibers and the like. Moreover, it has a strong interaction with cations and can be easily crosslinked, making it suitable for ion exchange and highly moisture-absorbing materials, and exhibits strong resistance to mold and mold growth. Therefore, it is expected to have a wide range of applications.

Furthermore, since decomposition of the main chain of cellulose can be suppressed in the process of producing the present derivative from cellulose, if a cellulose with a high degree of polymerization is used as a starting cellulose raw material, one with a correspondingly high degree of polymerization can be synthesized. When molded using this cellulose derivative as a raw material, it is expected that molded products with excellent mechanical properties will be obtained.

Furthermore, since the cellulose derivative of the present invention has a chemically active carpoxyenal group, carbamoylether group, and hydroxyl group in the cellulose side chain, it is easy to form a complete crosslinked structure based on ionic and covalent bonds, and can be made insoluble in water. Therefore, the present cellulose I conductor may be dissolved in a suitable solvent, preferably
It can be spun into water or a low alkaline aqueous solution (dope), turned into α-fibers, and subjected to insolubilization treatment, or it can be formed into fibers etc. by mixing a chemical that can insolubilize the cellulose derivative in the dogu and spinning it. Is possible.

(g) Examples The present invention will be specifically described below with reference to Examples.

Example 1 A wood pulp with a degree of polymerization of 700 was vacuum dried at 60'C for 7 hours, 51I was collected, and immersed in a 30% by weight aqueous solution of caustic soda 4015' at 30°C for 15 minutes. The cellulose was squeezed until the weight of the caustic soda aqueous solution was 1.2 per weight of cellulose, and 0.5 mol of acrylonitrile was added per glucose residue in the cellulose, followed by stirring at 30°C for 40 minutes. After that, 20g of water was added and after 5 hours, it was neutralized with dihydrochloric acid aqueous solution and 100IV? It was transferred into methanol, precipitated and collected.

This product was converted into a carbamoyl ether group and a carbamoyl ether group according to the above-mentioned method for evaluating the degree of substitution. When the degree of substitution of the xyethyl group was measured, they were 0.05 and o, i, respectively.

The total degree of substitution was 0.15. 5% at this room temperature
Cellulose derivatives soluble in caustic soda aqueous solution have 5
% caustic soda aqueous solution.

Incidentally, no cyanoethyl group was detected from the infrared absorption spectrum.

Example 2 Cellulose adjusted to a degree of polymerization of 300 by sulfuric hydrolysis was dried in the same manner as in Example 1, 5 g was collected, and a 151% caustic soda aqueous solution with a concentration of 15% was added. for 15 minutes at 30°C.

The weight of the caustic soda aqueous solution is 1 per 1 of the weight of cellulose.
．． 5, added 90.5 mol of acronitrile per glucose residue in cellulose, and heated at 40°C to 25%.
Stir for a minute.

Then, 20I of water was added, stirred for 16 hours, neutralized with 2M of hydrochloric acid aqueous solution, and precipitated with 1001D of methanol.
Recovered.

The degree of substitution of the carbamoylethyl group and carboxyether group of the product was measured using the same method as in Example 1.
The product was soluble in an aqueous solution of 0.05 and 0.12, respectively.

Example 3 The cellulose/alkali compressed product obtained in Example 2 was transferred into a closed reaction apparatus, and after the system was heated to 75° C., the glucose residues of cellulose were exposed. ! Blow in 70.5 mol of acrylonitrile in gaseous form, seal and mix, and open after 5 minutes.
20 g of water was added, and the mixture was stirred for 16 hours while returning to room temperature (30° C.), neutralized with a dihydrochloric acid aqueous solution, and precipitated and recovered with 100 rILl of methanol.

In the same manner as in Example 1, the carbamoylethyl group and car? When the degree of substitution of xyethyl group was measured,
0.06 and 0.11, respectively, and the products were soluble in an aqueous solution of caustic soda. Vacuum dry for 3 hours, collect 5g,
1 at 30°C to 40I of caustic soda aqueous solution with a concentration of 0% by weight.
Soaked for 5 minutes. This mixture was pressed until the weight of the caustic soda aqueous solution was 5 to 1 of the weight of cellulose. By varying the amount of acrylonitrile added, 30°C
The reaction was carried out for 40 minutes. 15 liters of water was added, stirred for 16 hours, neutralized with 2+ thihydrochloric acid aqueous solution, and then transferred into 100 d of methanol to precipitate and collect. The recovered compound was air-dried, then vacuum-dried at 60°C for 7 hours, and then subjected to force analysis using a CHN-analyzer and neutralization titration method. The xyethyl group and carbamoylethyl group were determined. The results obtained are shown in Table-1.

In the margin table below, ○ indicates soluble, Δ indicates swelling, and X indicates insoluble. When the degree of substitution is 0.15 or more, it becomes soluble in alkali, and when it is 1.5 or more, it becomes difficult to dissolve in aqueous solvents.

Example 5 Cellulose 511 prepared in Example 4 was prepared by varying the concentration of the caustic soda aqueous solution in the range of 8 to 35% by weight.
It was immersed in the caustic soda aqueous solution 40I, and after 10 minutes, the weight of the caustic soda aqueous solution was 0 to 1 of the cellulose weight.
．． Each mixture was squeezed to a ratio of 8 to 5.0. The amount of acrylonitrile was changed to glucose residues 0,4~
The reaction was carried out in various amounts up to 10 mol, and the xyethyl groups and carbamoylethyl groups were quantified under the same conditions as in Example 1. Although there are differences in manufacturing conditions, the degree of substitution of xyethyl groups and carbamoylethyl groups on cellulose derivatives that exhibit water solubility and have no residual cyanethyl groups detected by infrared spectrophotometry. Regardless, in general, Cal? The substitution degree range of the xyethyl group was 0.1 to 0.7, and the substitution degree range of the carbamoylethyl group was 0.05 to 0.85.

Example 6 New celluloma derivatives with a total degree of substitution of 0.15 (4) obtained in Example 2 and a total degree of substitution of 0.71 (A3) obtained in Example 3 were each converted into 5th alkaline), and water (A3) dissolved in
The weight fraction of each new cellulose derivative (T) is 1
A dope containing the 2nd ratio (4) and the 27th ratio (A3) was obtained. A
= After the dope A3 is passed through an extruder, the dope A is extruded into an aqueous solution containing 59 g of aluminum chloride as a coagulant and a crosslinking agent using a nozzle with a hole diameter of 0.08 mm and 50 holes, and wound into a multi-fibrous form. I got something. In addition, A3 doping was performed using a single hole with a hole diameter of 0.2 waφ and 250 mm.
When the extruded and dried product was wound up in a cylinder heated to ~300°C, a yarn with extremely good gloss was obtained. Both side fibers were dyeable with cationic dyes. Further, the A3 dope was mixed with 20 parts by weight of lead acetate based on the butt part of the new cellulose fiber 1001, and a fiber obtained by dry spinning in the same manner showed high water absorption but was insoluble in water.

Example 7 The A2, A3, Ya4, and AlO derivatives obtained in Example 3 were each dissolved in tap water at a concentration of 20% by weight, and the same
It was placed in a bottle and covered with a sealon film.

When these were left at room temperature and observed for mold growth,
Mold appeared after 10 days on A2 and 50 days on A3, but
A4. No mold growth was observed in AIO for over 3 months.

Comparative Example 1 The product soaked in the caustic soda aqueous solution prepared in Example 1 was compressed so that the weight of the caustic soda aqueous solution was 5.5 relative to the weight of cellulose IK. The amount of acrylonitrile added was varied in the range of 2 to 7 moles per glucose residue of cellulose, and the reaction was carried out at 30°C. After 40 minutes, 15 g of water was added and aged for 16 hours. The reaction mixture was transferred to 100 d metal, precipitated, filtered, dried,
An attempt was made to dissolve it in water, but it did not dissolve. The reason for this is thought to be that too much water was added in the post-pressing stage, so that most of the acrylonitrile eventually transferred to side reaction products, and only a cellulose derivative with an extremely low degree of substitution was obtained. It should be noted that when the weight of the alkaline aqueous solution was 5.0 or more per cellulose weight 1, the experiment was possible as described above, but the experiment was impossible when the weight of the cellulose was 0.8 because it was difficult to squeeze the water.

Comparative Example 2 - Acrylonitrile was added at 30°C to the pressed product of the aqueous solution mixture of cellulose and caustic soda prepared in Example 1 in a range of 5.0 mol, and after 40 minutes, 15.9' of water was added, and the aging time was The products from 30 minutes and 20 minutes were precipitated in 100 ml of methanol, collected, and vacuum dried at 60° C. for 7 hours. When the water solubility of the product was examined, the compound aged for 30 minutes did not exhibit water ionicity. The compound aged for 20 hours showed water solubility, but as a result of infrared absorption spectral analysis, a semi-cyanoethyl group was confirmed.

Claims (1)

[Claims] 1. Contains only a carboxyethyl group and a carbamoylether group as R substituents, and the degree of substitution of each is 0.1 to 0.
7 and 0.05 to 0.85 with total substitutions of 0.15 to 1.
55. 2. The degree of substitution of the carbamoylethyl group is at least 0.
2, and the ratio of the degree of substitution of the carbamoylether group to the degree of substitution of the carboxyether group is 0.5 or more. 3. Cellulose is immersed in an alkaline aqueous solution with a concentration of 8 to 35% by weight and then squeezed to make the cellulose/alkaline aqueous solution weight ratio 110B to 115.0. Add moles of acrylonitrile, stir for 5 to 120 minutes at a temperature of θ to 80°C, then add water or an alkaline solution so that the raw material cellulose is 20 to 30% by weight, and stir for 1 to 18 hours.
It is characterized by aging to form a homogeneous solution, then precipitating with a precipitant after neutralization, or neutralizing after precipitation, containing only carboxyether groups and carbamoylethyl groups as substituents, and each having a high degree of N conversion. is 01-0.7 and 0
．． A method for producing a cellulose derivative having a total substitution degree of 0.05 to 0.85 and a total substitution degree of 0.15 to 1.55.