JPH0195101A - Manufacture of high-purity acid-type cellulose derivative - Google Patents

Abstract

PURPOSE:To produce a high-purity acid-type cellulose derivative, by arranging a solution of an anionic cellulose derivative in a solvent on the cathode side of the electrodes and an ion-exchange membrane or an ultrafiltration membrane as diaphragm thereby converting the cellulose into an acid-type. CONSTITUTION:An anionic cellulose derivative is dispersed into a solvent thereby allowing it to swell or dissolve. Thereafter it is arranged on the cathode side or, preferably, on both sides of the electrodes, and an ion-exchange membrane or an ultrafiltration membrane is arranged as diaphragm, thereby producing the aimed cellulose derivative of an acid-type. As the applicable anionic cellulose derivative, carboxymethylcellulose, sulfoethylcellulose, carboxymethylhydroxyethylcellulose, or the like can be mentioned. As the solvent, water or a mixed solvent of water and an organic solvent, or the like can be mentioned. As the organic solvent which is used together with water, 3C or lower alcohols, lower ketones, etc., can be mentioned.

Description

[Detailed description of the invention] (Industrial use!?) Unreleased 1 is a method for producing a high-purity acid-type cellulose derivative υ,
lff1.

(Prior Art) The acid form of anionic cellulose derivative uses itself as a starting material to produce 11 metals! In many cases, it is used by converting it into a mold, and in particular, recently, IU+ is expected to be used in the fields of fine chemicals such as medicine, cosmetics, and ceramics, so high purity is required for quality.

Examples of practical applications include anionic cellulose derivatives, such as the acid form of carboxymethylcellulose (hereinafter referred to as CMC) or calcium 1!4, as a disintegrating agent or bleaching agent for pharmaceutical tablets, and lithium IS! 8 and potassium 11! is a battery composition, ammonium 11! It has applications in ceramics/ingu, gypsum clay, phosphor films, large-scale dispersants, thickeners, protective colloids, etc., and also for other cellulose derivatives, II to each a J71 m.
JI wait is big.

(Problems to be Solved by the Invention) The acid type of conventional 7-ionic cellulose conductors is usually synthesized from the metal salt type of anionic cellulose derivative, and most of them are sodium salt type. .

Therefore, when referring to this as an acid, it is sulfuric acid! ! ! Is it possible to convert it into an acid form using a mineral acid such as an acid or an organic brew of carbon dioxide? This method is known for shells, but a large amount of 1 & dilute acid waste liquid is derived to wash and remove the remaining Fri acid. It requires a lot of work for neutralization treatment and 4x water treatment, and has problems with equipment corrosivity, pollution, and economic efficiency.

In addition, when the degree of substitution of ether groups in cellulose derivatives increases, they often become water-soluble even with acids1, for example, CM
In the case of C, when its DS becomes 2 or more, it becomes water-soluble, and in the method proposed in Japanese Patent Publication No. 80-17445, since the acid type CMC is in the form of an aqueous solution, it can be dissolved in an organic solvent such as 99% acetone. A method is described in which it is precipitated and taken out as IJ&M, but this requires rectification of the water-containing organic solvent generated, which is an extremely disadvantageous factor economically. Furthermore, as a disadvantage of the method using acids described in the same publication, it inevitably causes depolymerization of cellulose chains;
In particular, when stannic acids are used, esterification products may be produced, which may have unfavorable effects on physical properties.

(Means for solving the problem) When producing high-purity acid-type cellulose derivatives by electrodialysis, Unreleased 151 disperses anionic cellulose derivatives in a solvent.

A method for producing a high-purity acid-type cellulose derivative, which is characterized in that after swelling or dissolving, an ion exchange membrane or an ultrafiltration membrane is arranged as a diaphragm on the cathode of the electrode, preferably both electrodes, and the cellulose derivative is converted into an acid form. It is.

1 unreleased! The anionic cellulose derivatives used in II include CMC, sulfoethylcellulose (SEC), and carboxymethylsulfoethylcellulose (CMSEC).
, carboxymethylhydroxyethylcellulose (CM
HEC) etc.

These cellulose derivatives can be prepared using known methods such as If
In the case of CM C, cellulose raw material 1 for valves etc. is diluted with NaOH.
It is obtained by mercerizing with chloroacetic acid or the like and etherifying with chloroacetic acid or the like.

Pond substances can be similarly obtained by known methods.

The solvent used in the present invention is water or a mixed solvent of water and an organic solvent.

Examples of organic solvents to be used in combination with water include lower alcohols having 3 or less carbon atoms (for example, methanol, ethanol, 2-propatol, etc.), lower ketones gA (for example, acetone, etc.). Moreover, the mixing ratio is water/organic solvent=10 to 119,790 to 1 by weight.

The method for producing a high-purity acid-type cellulose derivative according to the present invention is a method in which a single-acid anionic cellulose derivative is dispersed, swollen, or dissolved in the above-mentioned solvent, and then converted into S-type by electrodialysis.

What is this electrodialysis? 1. Ordinary electrolysis! The electrodes are made of a material that does not cause redox reactions, preferably platinum, and a diaphragm is placed on the cathode or preferably on both electrodes, and the anionic cellulose derivative is introduced into the electrolytic cell as a sample solution. The metal ions are removed, and the desired gel or solid product is placed in the 7-node or anode diaphragm. It is something to do. Preferably, placing a diaphragm on both electrodes means that when a gel is formed on the anode, a small amount of low-molecular anion components contained in the gel are incorporated into the 7-node diaphragm, and a higher purity cellulose gel is added to the 7-node diaphragm. This is due to the purpose of producing it on the surface of the diaphragm.

Examples of the diaphragm include ion exchange membranes and ultrafiltration membranes.

(Effects of Development 11) The acid type cellulose derivative prepared according to the method for producing undeveloped IJIJ is as follows.

(1) It is an almost perfect acid type with a metal ion content of 0.1z or less, and has extremely high purity, with almost no salts such as salts present. (2) When it is returned to its original metal fil type. The viscosity of the aqueous solution is
It has excellent properties, such as the viscosity of an aqueous solution of the first metal type, which hardly decreases and hardly causes a decrease in the degree of polymerization of cellulose chains.

In addition, the production method of the present invention is less polluting than conventional acid treatment methods, and when converted into acid form using acid, even in the case of water-soluble acid form cellulose derivatives, gel-like or solid The shape can be separated and extracted with high yield and efficiency.

(Example) In the examples, r%1 is based on weight.

Example 1 Electrolysis device i using platinum plates for both electrodes! I (KIKU
SUIELECTRON [S C0RP, made, MOD
EL PAB 110-0.8 (the same applies to the following examples), and carboxymethylcellulose sodium J! 1 (commercial product Na-CMC, 0S-0,135,2
Viscosity of 1 ton 2% aqueous solution at 5°C: 3380-Pass; Below, all viscosity values are at 25°C.
Put 650g of the paste solution dissolved in 50% aqueous solution of A7Tone into an electrolytic cell so that 4z becomes cation exchange 11!2 to both electrodes.
(Asahi Kax&, manufactured by Aciplex-F) 0.6
A current of 5A was applied. II (Og) as a gel after 4 hours
yield was obtained.

The anhydrous weight of this gel was 22.8 g, and the residual sodium was 0.022%.

Also, put this gel in a 5% NaOH aqueous solution.

The viscosity of a paste prepared as a 2% aqueous solution of Na-CMC was measured.

The viscosity at this time was 3290 mPa*s.

Example 2 An electrolytic device using platinum plates for both electrodes was assembled, and 40% 2-propertool of 6% Na-CMC (O5-2,18,2x aqueous solution viscosity 1830 mPa e s) was prepared in advance. 1667 g of the aqueous solution was subjected to electrodialysis using an ultrafiltration membrane (manufactured by Toyo Soda, UF-300PS, molecular weight cut off: 300,000) placed on both electrodes. The gel was taken out in 10 portions and turned over, and 672 g of gel was obtained after 5 hours. The solid content of this gel is 82.3g, and the residual sodium is 0.0
It was 45%.

Additionally, 2-propatool was removed from this gel and 5% N
The viscosity of a paste prepared by adding 2% Na-CMC to an aOH aqueous solution was measured.

The viscosity at this time was 1800 mPa·S.

Example 3 An electrolysis device using platinum plates for both electrodes was assembled, and 4% Na
-CM C (DS San 1.40. 2z aqueous solution viscosity 550
0 mPa *S) 55% methanol aqueous solution 3000
g was subjected to electrodialysis using a cation exchange membrane (manufactured by Asahi Kasei Co., Ltd., Acipre, Kusu F) placed at the cathode.

A yield of 937.4 g as gel was obtained after IIIF.

The volatile content of this gel is 90.1% and the residual sodium is 0.
．． It was 037%.

Methanol was removed from this gel, and the viscosity of a paste solution prepared by adding 2% Na-CMC to a 5% NaOH aqueous solution was measured.

The viscosity at this time was 5370 mPa.

Example 4 An electrolytic device using platinum plates for both electrodes was assembled, and 6% sodium sulfoethyl cellulose fil (Na-3EC;
DS-0,85,2z aqueous solution viscosity 1f170 mPa*
4,500 g of a 60% aqueous methanol solution of s) was subjected to electrodialysis using an ultrafiltration filter 11' (manufactured by Toyo Soda, UF-300PS, fractional molecular ffi: 300,000) placed on both electrodes.

A yield of 1890 g as gel was obtained after 2 hours. The volatile content of this gel was 88.02, and the residual sodium was 0.0.
It was 11%.

Methanol was removed from this gel, and the viscosity of a paste solution prepared by adding Na-3EC to a 5% NaOH aqueous solution to give a concentration of 2% was measured.

The viscosity at this time was 1520 mPa*s.

Example 5 An electrolytic device using platinum plates for both electrodes was assembled, and 5% carboxymethylsulfoethylcellulose sodium 11! (
Na-CMS E C; S E substitution degree 0.58, CM
2!1 conversion degree 0.53. 2% aqueous solution viscosity 2230 +*
8,800 g of 50% 50% tanol aqueous solution of
, both electrodes are equipped with an ultraviolet filter 11Q (manufactured by Toyo fr lf!,
0F-300PS, fractionated molecule Q 300,000) was used for electrodialysis. After 90 minutes, 855 g of 7^ was obtained as a gel. The volatile content of this gel was 87.7$ and the residual sodium was 0.033%.

Ethanol was removed from this gel and 5% NaOi (
The viscosity of a paste solution prepared to have a concentration of 2% Na-CMSEC in an aqueous solution was measured.

The viscosity at this time was 2140 mPa*s.

Comparative example 1゜N a-CM C (DSJ, 85.2z aqueous solution viscosity 33
80 mPa * s) 17χH2S 0 at 28.0g
4,520g was added and acidified at 50°C for 5 hours. After separating excess acid, 1000 g of water was added to perform deacidification treatment, and this operation was repeated three more times. This waste acid liquid 3000
．． was neutralized with NaOH.

The amount of acid type CMC obtained by this method was +7.
[1g, residual sodium was 0.197L, residual sulfate ion was 0.82%.

In addition, acid yliC was added so that the concentration of Na-CMC was 2%.
The viscosity of a paste prepared by dissolving MC in a 5% NaOH aqueous solution was measured.

The viscosity at this time was 2200 sPaφS.

Comparative Example 2゜N a-CM C (OS-2, 18, 22 aqueous solution viscosity 1
830 mPa *s) 18 ZH2SO in 100g
Added 45,000g. CMC gradually began to dissolve, was completely dissolved in 2 hours, and was further acidified at 50° C. for 3 hours.

Next, 20,000 g of HX acetone was added to cause precipitation. Separate the precipitate and further add 95z acetone aqueous solution 3000c
Washed 5 times with c. Acid type CM obtained by this method
The amount of C produced was 55.7g, and the residual sodium was 0.
25X, residual sulfate ion is 0.81! Met.

In addition, the viscosity of a paste prepared by dissolving acid CMC in a 5% NaOH aqueous solution so that the concentration of Na-CMC was 2% was measured.

The viscosity at this time was 450 mPa*s.

The results of these Examples and Comparative Examples are summarized in Table 1.

Claims (3)

[Claims] (1) When producing a high-purity acid cellulose derivative by electrodialysis, an anionic cellulose derivative is dispersed, swollen, or dissolved in a solvent, and then an ion exchange membrane is applied as a diaphragm to the cathode of the electrode, preferably both electrodes. Or with an ultrafiltration membrane,
A method for producing a high-purity acid type cellulose derivative, characterized in that it is in an acid type. (2) The method according to claim (1), wherein the solvent is water or a mixed solvent of water and an organic solvent. (3) The method according to claim (2), wherein the organic solvent is at least one selected from the group consisting of lower alcohols having 3 or less carbon atoms and ketones.