JPS5941642B2 - Method for producing polysaccharide glycolate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polysaccharide glycolate.

It is already known that polysaccharide glycolic acetic acid can be produced by reacting polysaccharides with monochloroacetic acid.

The reaction in this case is carried out under an alkaline catalyst. In addition to granular polysaccharides such as starch, non-granular polysaccharides such as cellulose were also used as polysaccharides. The polysaccharide glycolate thus obtained is
Since it is a water-soluble and stable compound, it is used in various fields as a thickener, sizing agent, etc. Since polysaccharides are solids, and monochloroacetic acid is also alkali, it is considered necessary to use a solvent in order to smoothly proceed with the above-mentioned reaction.

Therefore, water was used as a solvent in ancient times. However,
When water is used as a solvent, the raw material polysaccharide or the produced polysaccharide is dissolved in water and the viscosity of the reaction system increases to zero, making it difficult to stir the reaction system. Large amounts of water must be used to facilitate stirring. However,
If a large amount of water is used, a large reactor is required, side reactions are likely to occur, and furthermore, it takes time and effort to separate the produced polypentasaccharide from water. Therefore, it becomes impossible to obtain the target object advantageously. Therefore, in order to compensate for this drawback, it was proposed to use an organic solvent instead of water. For example, Japanese Patent Publication No. 27-5295 uses a granular polysaccharide such as starch as a raw material, adds monochloroacetic acid or its salt and a caustic alkali, and then uses an organic solvent or an organic solvent and water as a solvent. It is proposed that the etherification reaction be carried out by adding a mixture of This publication states that the amount of organic solvent added in this case should be kept within the range of 4 to 20 moles per mole of glucose groups in dry starch, and that the amount of water should be in the range of 0 to 15 moles. There is. If we specifically consider the amount of organic solvent among these, even if we take methyl alcohol as an example, the amount of 0 is 0 for 100 parts by weight of polysaccharide.
Approximately 68 parts by weight of methyl alcohol will be used, and therefore the reaction will be carried out in the form of a slurry. In addition, Japanese Patent Publication No. 32-2496 discloses that a non-granular polysaccharide such as cellulose is used as a raw material, and monochloroacetic acid or the like is added to the polysaccharide to carry out the above-mentioned reaction. It states that the ratio of the four components of alkali, monochloroacetic acid, water, and organic solvent should be maintained within a certain range.

From these limitations, it is not possible to generally derive the quantitative ratio of water and organic solvent to cellulose, but when the examples in that publication are combined, the total amount of water and organic solvent to cellulose raw material is at least It is approximately 85% by weight. cellulose 1
Since a mixture of 85 parts by weight of solvent to 00 parts by weight exhibits a slurry-like state, this method also allows the reaction to proceed in a slurry-like state. In addition, the special public
Publication No. 92 describes that when producing soluble starch by reacting starch with monochloroacetate, the water content of the reaction system is adjusted to 15 to 31% of the total amount.

Combining the examples in the publication, the reaction is carried out by adding 25 to 90 parts by weight of water to 100 parts by weight of starch. In addition, caustic alkali is added here as an aqueous solution. For this reason, the starch swells in the areas where it comes into contact with the aqueous caustic solution, causing local gelatinization, making it difficult to obtain a uniform glycolate. As described above, in all conventional methods, the polysaccharide is dissolved or dispersed in water or an organic solvent, and sometimes the polysaccharide is swollen in water to carry out the reaction.

The inventor investigated whether it would be possible to react this in a solid state. The inventor discovered that when caustic alkali is added as a solid rather than in the form of an aqueous solution and the amount of water is reduced, the etherification of polysaccharides with monochloroacetic acid can surprisingly proceed smoothly in the solid state. I learned.
According to conventional wisdom, caustic alkali is added in a solid state,
It seems that if the polysaccharide raw material is made into a slightly moist powder state, the caustic alkali remains as it is and only a non-uniform etherified product is obtained. However, contrary to expectations, it was found that a uniform etherified product could be easily obtained. At this time, the amount of water at the initial stage of the reaction, including the amount of water originally contained in the polysaccharide raw material, is maintained at 20 parts by weight or less per 100 parts by weight of the polysaccharide raw material, and the organic solvent is It was found that it was necessary to add 5 to 40 parts by weight of. This invention was made based on such knowledge. This invention involves adding a solid caustic alkali as a caustic alkali at the beginning of the reaction when producing a polysaccharide glycolate by reacting a polysaccharide or its derivative with monochloroacetic acid or its salt in the presence of a caustic alkali,
To 100 parts by weight of a polysaccharide or its derivative, the water content is kept at 20 parts by weight or less, including the water originally contained therein, and 5 to 40 parts by weight of an organic solvent are added to carry out the reaction. The present invention relates to a method for producing polysaccharide glycolate, which is characterized by: The polysaccharide raw materials used in this invention method are polysaccharides and derivatives thereof.

Polysaccharides include both granular polysaccharides and non-granular polysaccharides. Here, granule-like polysaccharides refer to those having starch grains with a size of approximately 1 to 100 microns, and non-granule-like polysaccharides refer to those having no such starch grains. Granule-like polysaccharides include starches such as corn starch, potato starch, and wheat starch. Non-granular polysaccharides include cellulose, pregelatinized starch, locust bean gum, guar gum, tamarind gum, and the like. Derivatives of polysaccharides include derivatives obtained by etherifying polysaccharides such as alkylation, hydroxyalkylation, alkylhydroxyalkylation, etc., or derivatives obtained by esterifying polysaccharides such as acetylation, acylation, etc. . As the caustic alkali, caustic soda and caustic potash are used. These caustic alkalis need to be added in solid form. A solid state is a state that is not in solution. Therefore, the caustic alkali may be one that has absorbed water, and any caustic alkali that remains in a solid state even after absorbing water can be used. The reason for using solid caustic alkali is as follows. When a solution of caustic alkali comes into contact with a polysaccharide, the system in the contact area becomes the same as adding a large amount of caustic solution to a small amount of polysaccharide, and there is non-uniformity between the system and the part that did not come into contact. occurs. As a result, the polysaccharide swells only in the contact areas and does not swell in the non-contact areas, which may cause the reaction to become non-uniform.
However, if it is in a solid state, even if it comes into contact with the polysaccharide surface, the contacted polysaccharide surface will not partially swell, but will form an alkaline adduct after being dissolved in the water and organic solvent contained in the system. do. In addition, by stirring the reaction system,
Since the caustic alkali is constantly abraded by friction with the polysaccharide, the alkaline adduct can be formed uniformly. This is because the reaction can therefore be carried out uniformly. The amount of caustic alkali to be added is 2 to 6 per polysaccharide raw material.
The content shall be within the range of 4% by weight. The etherifying agent that reacts with the polysaccharide may be monochloroacetic acid or a salt of monochloroacetic acid.

As the salt of monochloroacetic acid, sodium salt, potassium salt, and ammonium salt can be used. The amount of etherification agent added varies depending on the desired degree of etherification, that is, degree of substitution, but is between 2.5 and 76% based on the polysaccharide raw material.
It is determined appropriately within the range of weight %. Although water is always required to carry out the method of this invention, it is not necessary to add water at the beginning of the reaction.

This is because the raw material polysaccharide always contains several percent by weight of water. The amount of water, including the water originally contained in the polysaccharide raw material, is 20% by weight or less based on the polysaccharide raw material. The reason for this is that if the water content exceeds 20% by weight, the polysaccharide is likely to be locally gelatinized by the action of caustic alkali. The method of this invention is characterized by not gelatinizing the polysaccharide until the end of the reaction. Therefore, in order to avoid gelatinization, 20% by weight of water is added at the beginning of the reaction. It is as follows. Various organic solvents can be used.

For example, alcohols, ketones, hydrocarbons, and halogenated hydrocarbons can be used. All of these are inert to etherifying agents and caustic alkalis. Among these, those with low boiling points are desirable. Preferred examples include methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, dioxane, hexane benzene, toluene, xylene, dichloromethane chloroform, carbon tetrachloride, trichlene, etc., used alone or as a mixed solvent of two or more. The amount of these organic solvents is within the range of 5 to 40% by weight based on the polysaccharide raw material. Reduce the water content to 20% by weight or less based on the polysaccharide raw material,
The reason why the organic solvent is 5 to 40% by weight is to maintain the polysaccharide raw material in a slightly moist state.

Is the total weight of water and organic solvent 70? If the water content exceeds 20% by weight, the polysaccharide raw material may become slurry-like, but if the water content is 20% by weight or less and the organic solvent is within the range of 5 to 40% by weight, the polysaccharide raw material will not become slurry-like. I don't get it. In the method of this invention, caustic alkali, an etherifying agent, and a solvent are added to the polysaccharide raw material, but the addition method and order are arbitrary as long as the caustic alkali is not dissolved in the solvent and added.

That is, by adding the solvent and etherification agent first,
The caustic alkali may be added later, or the solvent and the caustic alkali may be added first and the etherifying agent may be added later. There is an interval of about 30 minutes to 1 hour between the addition of the solvent and the addition of the caustic alkali, and sufficient stirring is continued during that time. Also, when adding solid caustic alkali later, add the caustic alkali little by little over a long period of time. In the process of this invention, it is necessary to add the above in the above proportions at the beginning of the reaction. The mixture thus obtained has a solid state with a slightly moist surface. Is that 20% by weight, including the water originally contained in the polysaccharide raw material? This is because the organic solvent is 5 to 40% by weight, and the total amount is only 60% by weight at most.
In the method of this invention, the above mixture is thoroughly stirred.

During this time, the caustic alkali is pulverized by friction with the polysaccharide raw material and dissolved by the solvent to form an alkaline adduct. This alkaline adduct reacts with monochloroacetic acid or its salt. In any case, caustic alkali does not locally gelatinize the polysaccharide raw material. If you raise the temperature in this state. The etherification reaction with monotaloracetic acid proceeds. In the method of the invention, after adding the above-mentioned raw materials, the mixture is maintained at a temperature of 40 to 90°C.

For this purpose, if necessary, the reaction vessel is heated externally.
The reason why the temperature is maintained at such a temperature is that below 40°C, the reaction rate is slow and it takes a long time to complete the reaction.On the other hand, above 90°C, due to the moisture contained in the system, This is because there is a risk that the product will gelatinize. When the polysaccharide raw material begins to react with monochloroacetic acid and caustic, the reaction generates heat, but it is possible to obtain a homogeneous product by cooling the outside of the container or adding chemicals little by little. can. In addition, since the solid surface of the caustic alkali is constantly polished by friction with the polysaccharide raw material, the reaction does not stop midway and progresses gradually to the end. After the reaction is complete, an acid such as acetic acid is added to the polysaccharide produced to adjust the PII to 7.

Thereafter, in order to remove the added organic solvent or water, the product is dried under reduced pressure to obtain a product. According to the method of this invention, a small amount of water and an organic solvent are used, and the total amount thereof is 60% by weight or less based on the polysaccharide raw material, even including the water contained in the polysaccharide raw material, and the solvent Since most of the solvent is an organic solvent, the etherification reaction with monochloroacetic acid can be carried out smoothly to the end while keeping the polysaccharide raw material slightly moist. As a result, according to the method of the present invention, it is possible to efficiently and easily carry out the reaction without requiring a large-capacity reactor, while suppressing side reactions. Furthermore, the solvent can be easily removed after the reaction is completed. The method of the invention thus provides numerous advantages. Moreover, the products obtained by the method of the present invention have uniform and good quality that is as good as, if not better than, conventional products, and can be used for various purposes in the same way as conventional products. Therefore, the method of this invention has high practical value. The process of the invention can also be carried out following the hydroxyalkylation of granular polysaccharides such as starch under organic amine catalysts. Also,
By adding 0.001 to 0.1% by weight of a crosslinking agent to the polysaccharide raw material and carrying out the method of this invention, an alkali polysaccharide glycolate of any viscosity can be produced. Examples of crosslinking agents are epichlorohydrin, diglycidyl ether. Next, the method of the present invention will be explained with reference to Examples.

The extent to which the resulting product contains monochloroacetic acid components is indicated by the degree of substitution, and whether the product is homogeneous is determined by the transparency of the aqueous solution when dissolved in water. This aqueous solution was passed through a 200 mesh screen to see if any residue was formed on the screen. The method for measuring the degree of substitution is as per R. W. Written by Eyler,
Analytical Chemistry 9, 24 (
1947) was used as a reference. Example 1 In this example, no water was added other than the water contained in the raw material polysaccharide.

In an airtight container, add corn starch (moisture content: 13.5
%) 10009, isopropanol 1009, and monochlorosodium acetate 2079 were added and stirred for 30 minutes.

Thereafter, solid caustic soda 719 was added thereto, and after further stirring for 30 minutes, the temperature was raised to 80°C and stirring was continued for 3 hours, during which time the temperature was maintained at 80°C to carry out the etherification reaction. After the reaction was completed, the PI{ was adjusted to 7 with acetic acid, and the mixture was dried under reduced pressure for 30 minutes to obtain carboxymethyl starch as a product.

The degree of substitution of this product is 0.28, and the reaction efficiency is 85%.
It was recognized that it was good. When the product was dissolved in water, it became uniformly transparent and when passed through a 200 mesh screen. No residue was observed. Furthermore, the viscosity of the 4% aqueous solution of the product was 4000 centipoise, and both were recognized to be of good quality. Example 2 In this example, corn starch with an even lower moisture content was used, and the process was carried out in the same manner as in Example 1, except that an organic solvent and solid caustic soda were added at the same time.

That is, corn starch 10009 with a moisture content of 10%, methanol 1009, monochloroacetic acid sodium 2079, and solid caustic soda 719 were added simultaneously to a sealable container, and the container was sealed and stirred for 30 minutes.

Then, the temperature was raised to 80°C and stirred for 3 hours, during which time the temperature was raised to 80°C.
The temperature was maintained at 0°C and the reaction was carried out. After the reaction is complete, pl{
was adjusted to 7 and dried under reduced pressure for 30 minutes to obtain a product.

The degree of etherification due to glycolic acid groups in the product is 0.24, and the reaction efficiency is 75? It was hot. Further, when the product was dissolved in water, it became a homogeneous and transparent aqueous solution, which was passed through a 2000 mesh screen, but no residue was observed. The viscosity of the 4% aqueous solution was 4000 Cps Example 3 In this example, in addition to monochloroacetic acid, epichlorohydrin was simultaneously added as a crosslinking agent to carry out the reaction.

Corn starch (moisture content 13.5%) in an airtight container
) 10009, and then add isopropanol 1
A mixed solution of 509, monochloroacetic acid 1689, and epichlorohydrin 0.19 was added and stirred for 30 minutes.

Next, solid caustic soda 14 is added while cooling the outside.
29 was added little by little over 2 hours. After continuing to stir for 1 hour, the temperature was raised to 60° C. and the reaction was carried out with stirring for 4 hours. During this time, the temperature was maintained at 60°C. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the product was dried under reduced pressure for 30 minutes to obtain a product. The degree of substitution of the product is 0.28, the reaction efficiency is 84%, and the aqueous solution of the product is homogeneous and transparent.
No residue was observed with the 200 mesh screen. The viscosity of the 4% aqueous solution was 9000 cps.

Example 4 In this example, starch was hydroxyalkylated with propylene oxide and then glycolic acid etherified with monochloroacetic acid.

First, put corn starch (moisture content 13,
After adding 5%) 10009 and sealing, 100mmH
It was degassed under reduced pressure to g. Next, the valve was opened and 10 g of triethylamine was injected, followed by stirring for 30 minutes. After 30 minutes had passed, the valve was opened and propylene oxide 209 was injected, and then the temperature was raised to 70° C. and stirred for 2 hours. Meanwhile, the temperature was maintained at 70-80°C to hydroxypropylate the starch. Thereafter, the container was cooled, a mixed solution of isopropanol 1509 and monochloroacetic acid 1689 was added, and the mixture was stirred for 30 minutes.

Next, solid caustic soda 14 was added while cooling the outside with ice.
29 was added little by little over 2 hours. After continuing to stir for 1 hour, the temperature was raised to 6°C, and the mixture was reacted with monochloroacetic acid while stirring. During this time, the temperature was maintained at 6'C. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the product was dried under reduced pressure for 30 minutes.

The degree of substitution of the product was 0.30, and the reaction efficiency was 90%. Further, the viscosity of a 4% aqueous solution of the product was 4000 cps, the aqueous solution was uniform and transparent, and no residue was observed when using a 200 mesh screen. Example 5 In this example, a polysaccharide raw material was hydroxypropylenized with propylene oxide and then etherified with monochloroacetic acid.

Potato starch (moisture content 15%) 1,000 ml in an airtight container
9 was added and sealed, and the pressure was reduced to 100 mmHg. Next, after opening the valve and injecting triethylamine 109, the mixture was stirred for 30 minutes. After 30 minutes, the valve was opened, propylene oxide 309 was injected, the temperature was raised to 70°C, and the reaction was continued with stirring for 2 hours.
During this time, the temperature was maintained at 70°C. After the reaction is complete, cool the container and add isopropanol 1509 and monochloroacetic acid 16
A mixed solution of 89 and 0.1 g of shrimp chlorohydrin was added and stirred for 30 minutes.

Then, while cooling the outside with water, solid caustic soda 14
2f7 was added in portions over 2 hours. After that, stirring was continued for 1 hour, and then the temperature was raised to 60°C, and stirring was continued for 3 hours to carry out the reaction at 60°C. After the reaction is complete, add P with acetic acid.
The H was adjusted to 7 and dried under reduced pressure for 30 minutes to obtain a product. The degree of substitution of the product was 0.32, the reaction efficiency was 94%, the product was dissolved in water to form a homogeneous and clear solution, and no residue was observed by 200 mesh screen.

Further, the viscosity of the 4% aqueous solution was 10,000 cps.
Example 6 Cellulose powder (moisture content 6%) 10009 in a ball mill
509 methanol and 80 fl of solid caustic soda were added thereto, and the mixture was rotated for 2 hours.

After transferring the contents to an airtight container and sealing it,
It was degassed under reduced pressure to mmHg. Next, open the valve and use propylene oxide 170f! was injected, the temperature was raised to 70°C to start the reaction, the temperature was maintained at 70 to 90°C, and the reaction was continued for 3 hours with stirring. After the reaction is complete,
The container was cooled, solid caustic soda 1009 and isopropanol 1009 were added, and the mixture was stirred for 30 minutes.

Next, monochloroacetic acid soda 5179 was added and the mixture was stirred for 30 minutes. Thereafter, the temperature was raised to 60° C. to start the reaction, and the reaction was carried out at 60° C. for 4 hours while stirring was continued. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the product was dried under reduced pressure for 30 minutes to obtain a product. Product substitution degree is 0.65
And the reaction efficiency is 85? It was hot.

The product dissolved in water to produce a homogeneous clear solution, with no residue observed through a 200 mesh screen.
The viscosity of the 4% aqueous solution was 8000 cps.

Example 7 In this example, guar gum was used as a polysaccharide raw material and etherified with sodium monochloroacetate.

Guar gum (moisture content 10%) 1000 g in an airtight container
Methanol 1409 was added to 9 and stirred for 30 minutes.

Thereafter, solid caustic soda 1109 was added thereto, and the mixture was further stirred for 30 minutes. Then, after adding monochloroacetic acid soda 2689 and stirring for 30 minutes, the internal temperature was lowered to 60℃.
℃ and continued stirring for 5 hours, during which time the internal temperature was kept at 60℃.
The etherification reaction was carried out by maintaining the temperature at After the reaction was completed, the pH was adjusted to 7 with acetic acid, the internal temperature was raised to 80° C., and the mixture was dried under reduced pressure for 30 minutes to obtain carboxymethyl guar gum as a product.

The degree of substitution of this product is 0.31, and the reaction efficiency is 75%.
It was recognized that it was good. When the product was dissolved in water, it was uniformly and transparently dissolved, and no residue was observed when it was passed through a 200 mesh screen. In addition, the viscosity of the 4% aqueous solution of the product is 10,000 centipoise,
All products were recognized as being of good quality. Example 8 In this example, defatted tamarind gum was used as the polysaccharide and etherified with sodium monochloroacetate.

Defatted tamarind gum (moisture content: 10
%) 1000f! and isopropanol 1509. Sodium monochloroacetate 2689 was added and stirred for 30 minutes.

Next, 110f of solid caustic soda! After stirring for 30 minutes while cooling the outside, the internal temperature was raised to 60°C and stirring was continued for 6 hours, during which time the internal temperature was maintained at 60°C to carry out the etherification reaction. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the mixture was dried under reduced pressure for 1 hour to obtain carboxymethyl tamarind gum as a product.

The degree of substitution of this product is 0.34, and the reaction efficiency is 80%.
It was recognized that it was good. When this product was dissolved in water, it was uniformly and transparently dissolved, and no residue was observed when it was passed through a 200 mesh screen. In addition, product 4
The viscosity of the % aqueous solution was 8000 centipoise, and all were recognized to be of good quality. Comparative Example 1 In this comparative example, 20% by weight or more of water and 400% by weight of an organic solvent were used with respect to the polysaccharide raw material, and caustic soda was added in the form of an aqueous solution.

Corn starch (moisture content 13.5%) 10009,
Isopropanol 41 was added, and a mixed solution of caustic soda 1429 and water 2009 was added while stirring. While cooling the outside with ice, slowly add 168f1 of monochloroacetic acid and stir for 1 hour. After the contents were transferred to a sealable container and sealed, the temperature was raised to 70°C to start the reaction, and stirring was continued for 3 hours to allow the reaction to occur at a temperature of 70°C. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the solvent was filtered off.
A product was obtained by drying under reduced pressure for 3 hours.

The degree of substitution of the product was 0.28, and the reaction efficiency was 85%. Further, the product dissolved in water to produce a homogeneous and transparent aqueous solution, and no residue was observed by a 200 mesh screen. The viscosity of the 4% aqueous solution was 5000 cps.

Compared to Example 1, this comparative example had disadvantages in that it required a large-capacity reaction vessel and was not easy to stir.
Comparative Example 2 In this comparative example, including the water contained in the polysaccharide raw material,
Slightly more than 20% by weight based on the polysaccharide raw material. Caustic soda was also added in the form of an aqueous solution.

Sodium monochloroacetate 3469 was added to corn starch (moisture content 13.5%) 10009 and mixed for 3 hours using a powder mixer. The mixture was transferred to a sealable container and, with stirring, a solution of caustic soda 1199 in water 1009 was sprayed onto it over a period of 2 hours with stirring.
After the spraying was completed, the temperature was raised to 40° C. while stirring to start the reaction, and the reaction was continued at 40° C. for 15 hours. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the mixture was dried under reduced pressure for 1 hour to obtain a product. The product had a degree of substitution of 0.25 and a reaction efficiency of 45%.

In addition, when the product is dissolved in water, there are many particulate undissolved components,
Many residues due to the 0 mesh screen were observed. 4
% aqueous solution was 10,000 cps.

Claims (1)

[Claims] 1. When manufacturing a polysaccharide glycolate by reacting a polysaccharide or its derivative with monochloroacetic acid or its salt in the presence of a caustic alkali, at the beginning of the reaction, add a solid state as a caustic alkali, % of the polysaccharide or its derivative, the water content is kept at 20 parts by weight or less, including the water originally contained therein, and the organic solvent is kept at 5 parts by weight or less.
A method for producing polysaccharide glycolate, which comprises adding from 40 parts by weight to carrying out the reaction.