KR101526248B1 - A method for manufacturing hydroxyalkyl polysaccharide by dry-reaction - Google Patents

Abstract

More particularly, the present invention relates to a method for producing a highly substituted hydroxyalkyl polysaccharide by dry reaction, and more particularly, to a method for producing a highly substituted hydroxyalkyl polysaccharide by spraying an alkali saturated aqueous solution to a polysaccharide having low water content, Substituted hydroxyalkyl polysaccharides which can greatly improve the productivity by a continuous reaction even by a simple process by carrying out a hydroxyalkylation reaction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a process for preparing a hydroxyalkyl polysaccharide by a dry reaction,

More particularly, the present invention relates to a method for producing a highly substituted hydroxyalkyl polysaccharide by a dry reaction, and more particularly, to a method for producing a highly substituted hydroxyalkyl polysaccharide by a dry reaction in which an alkaline saturated aqueous solution is spray- Substituted hydroxyalkyl polysaccharides which are capable of greatly improving productivity by a continuous reaction even by a simple process by performing a hydroxyalkylation reaction.

Most of the polysaccharides are in powder form, so they must be suspended or dissolved with a suitable solvent in order to hydroxyalkylate them. Generally, solvents used for the hydroxyalkylation of polysaccharides are largely divided into organic solvents and water. Among the above methods, a suspension method using an organic solvent (hereinafter referred to as an 'organic solvent method') is a method in which a large amount of an organic solvent is used, usually in an amount of 1 to 2 times or more, relative to the amount of the raw material and water is used as a solvent Method "), water is used at least 2 to 5 times the amount of the raw material. Therefore, even if any of the above two methods is adopted, a very large amount of solvent is required. On the other hand, in the hydroxyalkylation reaction using the solvent, since the final reactant is kept in a slurry or paste form, the target product is recovered by filtration or precipitation using a large amount of an organic solvent.

As a conventional technique for the hydroxyalkylation of polysaccharides, US Pat. No. 2,496,670 discloses a process for producing a hydroxyalkyl ether of a polysaccharide by a purifying method. Since water is used as a solvent, an organic solvent However, since the hydroxyalkyl ether of the desired polysaccharide is a water-soluble polymer, the reaction product is dissolved in water when the reactivity is increased. There is a problem that the viscosity of the reaction system rises sharply, so that the reaction system becomes uneven and a very strong mechanical load is applied, so that it is troublesome to add a large amount of water into the reaction system in order to solve this problem.

The disadvantages of the above-described acceptance method are briefly summarized as follows: 1) a large amount of reaction apparatus is required, 2) side reactions may occur, 3) reaction efficiency is extremely low (about 10 to 60% , And 4) special equipment for reactant recovery (eg, drum drier, spray dryer, another settling tank, solvent recovery unit, separator, etc., in the case of sedimentation of solvent). As described above, the disadvantage of the above-described method of purchasing is that it is impossible to manufacture an economical hydroxyalkylated polysaccharide by mass production because the equipment is mass-produced and the process efficiency is very low when the use method is used, .

On the other hand, U.S. Patent No. 3,326,890 discloses an organic solvent method. In this method, an attempt has been made to solve the problem of the above-described method by facilitating stirring using the property that the polysaccharide is well dispersed in an organic solvent , There is still a problem that a large-scale reaction apparatus is required although a large amount of organic solvent is used, which is not the same as the reaction apparatus used in the receiving method. In addition, uneconomical problems such as fire problems caused by organic solvents, environmental problems due to imperfect recovery, and demands for special devices for recovering used organic solvents have not yet been solved. In addition, the quality of the produced product is low, side reactions are likely to occur, and the reaction efficiency is low to about 40 to 50%, so that the problem of the purchasing method has not been completely solved.

In addition, as a method for overcoming the problems of the above-mentioned receiving method and organic solvent method, Japanese Patent Laid-Open Publication No. 53-39386 discloses a method for producing a hydroxyalkyl ether of starch in an anhydrous state by using an organic amine as a catalyst (Hereinafter referred to as a " dry method ") is disclosed. However, this method has a problem in that a large amount of an organic solvent is used and a large amount of organic solvent is used to recover the alkali.

Therefore, in order to solve the problems of the dry method using the alkaline catalyst, Korean Patent Laid-Open Publication No. 1999-0046174 discloses a method in which caustic soda and propylene oxide on flake, which are alkali catalysts, are added to guar gum and mixed with a small amount of water However, in the hydroxyalkylation reaction, when the alkali catalyst and water are brought into contact with the guar gum, a large amount of small starch is generated due to the occurrence of gelation, and the reaction should be carried out after drying, grinding and bifurcation .

In Korean Patent Laid-Open No. 2001-0068171, tamarind gum is subjected to cross-linking and carboxymethylation reaction using a minimum amount of methanol as a reaction solvent to secure homogeneity of reaction and reduce the amount of undissolved product. However, in this case, due to the physical properties of the moist reactant, a coating layer in the reactor is formed during the reaction, which makes it difficult to perform a continuous reaction, and organic solvent recovery and treatment methods still remain.

Korean Patent Laid-Open No. 2006-0074755 proposes a method in which an alkaline catalyst prepared by mixing an aliphatic glycol and a 50% NaOH solution is subjected to a hydroxyalkylation reaction to obtain homogeneous reaction . However, this method has a problem that a coating layer is formed in the reactor and another problem that an aliphatic glycol remains in the starch.

1. US Patent No. 2,496,670 2. US Patent No. 3,326,890 3. Japanese Patent Publication No. 53-39386 4. Korean Patent Publication No. 1999-0046174 5. Korean Patent Publication No. 2001-0068171 6. Korean Patent Publication No. 2006-0074755

As a result of long research to solve the above problems, it has been found that a water-saturated alkaline solution is spray-mixed with a low-moisture polysaccharide, and then hydrolyzed by a dry reaction by adding an alkylene oxide The inventors of the present invention have found that it is possible to produce a highly substituted hydroxyalkyl polysaccharide by a simple process without a subsequent process and to improve the productivity by continuous reaction. Thus, the present invention has been completed.

It is therefore an object of the present invention to provide an improved process for preparing hydroxyalkyl polysaccharides which are highly substituted from polysaccharides by a dry process of new conditions.

Another object of the present invention is to provide a method for producing a hydroxyalkyl polysaccharide which is highly substituted by an economical and simple method, which can be produced by a simple production apparatus and can be carried out without any subsequent process such as drying, crushing and bifurcation processes.

Still another object of the present invention is to provide a method for producing a hydroxyalkyl polysaccharide highly substituted by a dry method at a high reaction efficiency without using an organic solvent for catalyst dispersion, which can greatly improve productivity by a continuous reaction.

In order to solve the above problems, the present invention provides a method for preparing a polysaccharide, comprising: preparing a low moisture powder polysaccharide having a moisture content of 11% by weight or less; Spraying an alkaline saturated aqueous solution having a concentration of 30 to 70% with a catalyst; Aging the mixture in which the catalyst is spray-mixed with sealing; Substituted hydroxyalkyl polysaccharides by a dry reaction, comprising the step of subjecting a hydroxyalkyl alkylene oxide to a hydroxyalkylation reaction.

The method for preparing a highly substituted hydroxyalkyl polysaccharide according to the present invention is characterized in that an alkali-saturated aqueous solution is used as a catalyst in a low-moisture polysaccharide, followed by aging, followed by hydroxyalkylation by a dry reaction, There is no need to use an organic solvent for catalyst dispersion, and the reaction efficiency is extremely high.

In addition, by newly forming the conditions of the dry reaction, it is possible to obtain a reactant in the form of uniform powder particles without lumps even during the reaction, and it is possible to produce the desired product with high reaction efficiency even if the drying, Is a very economical and simple way to simplify manufacturing facilities and processes.

In addition, since the coating layer is not formed in the reactor during the dry reaction process, the continuous reaction operation can be performed without washing the reactor, so that the productivity can be greatly increased.

In particular, it is possible to prevent the generation of wastewater due to a cleaning operation such as water cleaning when forming a coating layer in a reactor, and it is not necessary to use an organic solvent as a catalyst diffusion agent, which is a very environmentally friendly manufacturing method.

Hereinafter, the present invention will be described in more detail as an embodiment.

The present invention is characterized in that a hydroxyalkylated polysaccharide is prepared by spraying a low-moisture polysaccharide with an alkali saturated aqueous solution having a concentration of 30 to 70% by a catalyst, and aging the hydroxyalkylated polysaccharide in a closed state followed by hydroxyalkylation reaction .

In the present invention, in the step of preparing a low moisture powder polysaccharide having a moisture content of 11% by weight or less, it is preferable to use a commercially available polysaccharide or a low moisture polysaccharide containing 11% by weight or less of water, . Here, the polysaccharide is a vegetable gum polymer which is a cold water-soluble and insoluble natural polymer, and may be, for example, one or a mixture of two or more selected from starch, guar gum, tamarind gum, locust gum gum and its modified products or derivatives thereof.

The polysaccharide used in the present invention should be a low-moisture polysaccharide. The reason why the low-moisture polysaccharide is used is that the aqueous alkaline solution of the catalyst maintains a uniform particle state without occurrence of gelation upon contact. According to the present invention, it is preferable to use a low-moisture polysaccharide having a water content of not more than 11% by weight, more preferably not more than 8%, and more preferably 0.1 to 5% . In the case of using a polysaccharide having a water content higher than that of the polysaccharide without using a low-moisture polysaccharide, there is a problem that a uniform particle state can not be maintained due to the occurrence of agglomeration in the process of contacting an alkaline saturated aqueous solution used as a catalyst, Lt; / RTI >

In the present invention, a low-moisture polysaccharide prepared as described above is spray-mixed with an alkali saturated aqueous solution having a concentration of 30 to 70% by a catalyst. Examples of the alkaline saturated aqueous solution used as the catalyst include a saturated aqueous solution of an alkali metal, an alkaline earth metal, oxides and hydroxides thereof, and a water-soluble inorganic salt composed of a strong base and a weak acid. More specific examples of the alkali component used herein may include alkali metals selected from sodium and potassium, alkaline earth metals selected from calcium and magnesium, and examples of the hydroxide or oxide thereof include sodium hydroxide, sodium oxide, calcium hydroxide, magnesium hydroxide Can be preferably used. As inorganic salts composed of strong bases and weak acids, sodium carbonate and the like can be preferably used.

The saturated aqueous alkaline solution used as the catalyst according to the present invention should have a saturation concentration of 30 to 70%. In the case of a supersaturated aqueous solution, it is difficult to spray the catalyst aqueous solution due to crystal formation. If the solution is unsaturated, There is a problem in that the polysaccharide is agglomerated in the process of instant contact with the polysaccharide to cause agglomeration of the reactant. More preferably, an alkali saturated aqueous solution having a concentration of 35 to 55% is preferable.

According to the present invention, it is preferable to use an alkaline saturated aqueous solution adjusted to a saturated concentration according to the temperature, more preferably an alkaline saturated aqueous solution adjusted to a saturated concentration at 0 to 70 ° C. As described above, it is preferable that the alkaline saturated aqueous solution catalyst is injected into the polysaccharide by adjusting the concentration for each temperature so as to become a saturated aqueous solution. As a preferred embodiment considering the correlation between the temperature and the concentration of the alkaline saturated aqueous solution, for example, in the case of using caustic soda as the alkali, 67% concentration), more preferably 0 캜 (30% concentration) to 30 캜 (53% concentration). If the temperature of the catalyst is too low or too high, unnecessary energy is excessively consumed to control the process. If the temperature of the catalyst is too low, formation of crystals due to supersaturation will make it difficult to spray the catalyst aqueous solution. There is a problem of deterioration. If the concentration is lower than the saturation concentration, polysaccharide is agglomerated at the time of the instantaneous contact of the catalyst due to unsaturation, resulting in generation of agglomerates of reactants.

According to the present invention, such a catalyst component is preferably spray-mixed with 1 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the low-moisture polysaccharide. If the amount is too small, there is a problem that the effect of application of the catalyst is insufficient, and if it is too much, there is a problem of entanglement and the like.

According to the present invention, the mixture in which the catalyst is spray-mixed as described above is characterized in that it is subjected to a step of aging under tightly closed conditions.

In the present invention, this aging step is carried out so that the catalyst aqueous solution is sufficiently diffused into the particles after the catalyst aqueous solution (alkali saturated aqueous solution) is spray-mixed with the polysaccharide, so that a uniform reaction is achieved during the hydroxyalkylation reaction. This aging is advantageous for effective aging conditions, which are advantageous for diffusion of the catalyst and formation of uniform reaction conditions, in an airtight condition. Under such sealing conditions, the temperature for aging is 0 to 50 캜, more preferably 20 to 35 캜. If the aging temperature is lower than 0 ° C, moisture contained in the catalyst solution is difficult to diffuse into the polysaccharide particles due to crystallization, and the catalyst may exist only on the surface, resulting in nonuniform reaction. When the temperature is higher than 50 ° C, There is a problem that the decomposition reaction occurs with the organic solvent to lower the viscosity and lower the color. The aging time is preferably 4 hours or more, and more preferably 10 to 20 hours. If the aging time is too short, the extent to which the catalyst aqueous solution diffuses into the polysaccharide particles is insufficient, which may lead to a non-uniform reaction at a later hydroxyalkylation reaction.

According to the present invention, after the catalyst is mixed and aged, an alkylene oxide is added to conduct a hydroxyalkylation reaction.

In the present invention, alkylene oxide is used as a reaction reagent for hydroxyalkylating polysaccharides. As the alkylene oxide used herein, a lower alkylene oxide having 2 to 7 carbon atoms is preferably used. More specifically, for example, ethylene oxide, propylene oxide, 1,2-butylene oxide or butadiene monoxide More than one selected may be used. Most preferably, propylene oxide which can be added to the reaction system in a liquid state at room temperature is used.

According to the present invention, the amount of such alkylene oxide to be used can be varied depending on the degree of modification required, but preferably 0.01 to 3.0 mol / mol, more preferably 0.1 to 2.5 mol / mol anhydroglucose per mol of the polysaccharide . If the amount of the alkylene oxide to be used is less than 0.01 mol ratio per unit of anhydrous glucose, there is a problem in obtaining the water-solubility (cold water swelling property) of the object, and when it exceeds 3.0 mol ratio, the side reaction and the reaction efficiency are deteriorated.

The reaction is preferably carried out at a temperature of 40 to 120 ° C, more preferably 50 to 90 ° C. The reaction time for carrying out such a hydroxyalkylation reaction is preferably carried out for a sufficient time necessary for achieving the required degree of substitution, more preferably 0.5 to 12 hours.

By performing the hydroxyalkylation reaction as described above, the desired highly substituted hydroxyalkyl polysaccharide of the present invention can be obtained. The highly substituted hydroxyalkyl polysaccharides obtained according to the present invention can be obtained with hydroxyalkyl polysaccharides in a highly substituted state having a degree of substitution (MS) of at least 0.70.

Particularly, according to the present invention, it is possible to obtain a reactant having a high reaction efficiency in powder phase without conventional drying, pulverization and bifurcation steps after the hydroxyalkylation reaction as described above, thereby simplifying the manufacturing process, When produced by a dry reaction, a highly substituted hydroxyalkylated polysaccharide can be obtained as a reaction product on powder particles homogeneous without lumps without drying, grinding and blooming processes required for production.

Therefore, the method for preparing the highly substituted hydroxyalkylated polysaccharide by the dry reaction according to the present invention can omit the drying, crushing and blooming apparatuses, thereby remarkably reducing the production facility investment cost.

Also, according to the production method of the present invention, a uniform reaction can be performed during the reaction, and in particular, a coating layer is not formed in the reactor, so that a continuous reaction process can be performed and productivity can be greatly increased.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the Examples.

Examples 1 to 6: Preparation of hydroxypropyl starch and guar gum

(Moisture content: 10.3%, 9.2%, and 4.0 wt%) were added to a laboratory reactor (Hanyang Machinery Co., Ltd.) having a volume of 30 liters equipped with a low speed stirrer (30 rpm) % Of guar gum was placed in each batch, and 565 g of a saturated aqueous sodium hydroxide solution having a concentration of 34% at 4 캜 was finely sprayed and mixed. The mixture was allowed to stand at 25 캜 for 15 hours in an airtight state and then aged. The aged material was subjected to removal of air in the reactor by a general method and filled with nitrogen, followed by addition of 1,357 g of propylene oxide, followed by stirring for 1 hour. The mixture was heated at 80 ° C for 3 hours and cooled to room temperature to prepare hydroxypropyl starch and guar gum, respectively.

Examples 7 to 10: Preparation of hydroxypropyl starch and guar gum by changing catalyst composition

The corn starch having a moisture content of 3.4% and guar gum having a moisture content of 4.0% were used in the same manner as in Examples 1 to 6. The temperature and concentration of the caustic soda-saturated aqueous solution catalyst were adjusted to 53.0% Hydroxypropyl starch and guar gum were prepared in the same manner except that a saturated sodium hydroxide aqueous solution having a concentration of 65.0% at 55 캜 was used.

Example 11: Preparation of hydroxypropyl starch by continuous batch reaction in a 3000 L reactor

500 kg of corn starch (manufactured by Samyang Genex) having a moisture content of 4.8% was put into a field reactor (Hanyang Machinery Co., Ltd.) having a content volume of 3000 L equipped with a low speed stirrer (30 rpm), and 57 Kg of a 50% And the mixture was allowed to stand at 25 占 폚 for 15 hours in a closed state to be aged. After removing the air in the reactor by the general method and filling with nitrogen, 136 kg of propylene oxide was added and the mixture was stirred for 1 hour. The mixture was heated at 80 占 폚 for 3 hours and cooled to room temperature to prepare hydroxypropyl starch. In the same manner, the hydroxypropyl starch was prepared by reacting in 10 consecutive batches without reactor cleaning.

Example 12: Preparation of hydroxypropyl carboxymethyl tamarind gum by changing polysaccharide raw material, catalyst composition and aging conditions

Carboxymethyl tamarind gum (manufactured by ADGUMS) having a water content of 0.7% was used, and a saturated aqueous solution of 32% concentration at 2 ° C was used as the caustic soda catalyst under the same conditions as in Example 5, Hydroxypropyl carboxymethyl tamarind gum was prepared in the same manner except that it was sealed at 4 캜 and aged.

Example 13 Preparation of Hydroxypropylic Acid-Treated Starch by Changing Polysaccharide Raw Material, Catalyst Composition and Age Condition

Treated with starch (manufactured by Samyang Genex) having a water content of 0.5% and a saturated sodium hydroxide solution at a concentration of 69% at 65 ° C was used under the same conditions as in Example 5, Hydroxypropyl < / RTI > acid-treated starch was prepared in the same way except that it was sealed at 48 DEG C and aged.

Comparative Examples 1 and 2: Preparation of hydroxypropyl starch and guar gum using a raw material having a high water content

Hydroxypropyl starch and guar gum were prepared in the same manner as in Examples 1 to 6 except that corn starch having a moisture content of 11.7% and guar gum having a moisture content of 11.4% were used.

Comparative Examples 3 to 4: Preparation of hydroxypropyl starch and guar gum with different catalyst compositions

Corn starch having a moisture content of 3.4% by weight was used in the same manner as in Examples 1 to 6, and a supersaturated aqueous solution of caustic soda with a concentration of 69.0% at 61 DEG C and an aqueous solution of caustic soda with a concentration of 45.0% at 30 DEG C Hydroxypropyl starch and guar gum were prepared in the same manner.

Comparative Examples 5 to 6: Preparation of hydroxypropyl starch and guar gum without aging step

Corn starch having a moisture content of 3.4% and guar gum having a moisture content of 4.0% were used in the same manner as in Examples 1 to 6, except that they were reacted in the same manner except that they were not aged at 25 ° C. Even after the reaction with the hydroxypropyl itself did not occur.

Comparative Examples 7 to 8: Preparation of hydroxypropyl starch and guar gum by the dry method described in Korean Patent Publication No. 1999-0046174

5000 g of common corn starch (manufactured by Samyang Genex) or guar gum distributed in a laboratory reactor (Hanyang Machinery Co., Ltd.) having a volume content of 30 L equipped with a low-speed stirrer (30 rpm) was placed in each batch, After the air in the reactor was removed by a general method and nitrogen was charged, 1357 g of propylene oxide was added and the mixture was stirred for 1 hour. Then, 208 g of water was added, mixed at 75 to 80 캜 for 3 hours, and then cooled to room temperature. Thereafter, drying with an air stream dryer equipped with an impact mill was not further carried out in order to make the reactivity with the above-mentioned embodiments comparable.

Comparative Example 9: Production of hydroxypropyl starch by the dry method described in Korean Patent Publication No. 2006-0074755

5000 g of common corn starch (manufacturer: Samyang Genex) or guar gum distributed in a laboratory reactor (Hanyang Machinery Co., Ltd.) having a volume content of 30 L equipped with a general type low speed stirrer (30 rpm) was placed in each batch, and 225 g of propylene glycol And 150 g of 50% NaOH were injected and mixed for 30 minutes. After replacing with nitrogen in a sealed state, 1357 g of propylene oxide was added and reaction was carried out at 40 ° C for 8 hours.

Comparative Examples 10 to 11: Preparation of hydroxypropyl starch and guar gum by use of a catalyst whose saturation concentration was changed

Hydroxypropyl starch and guar gum were prepared under the same conditions as in Example 5 except that the concentration of caustic soda in the alkaline saturated aqueous solution as the catalyst was varied to 72% and 29%, respectively.

Comparative Example 12: Preparation of hydroxypropylated starch by changing the aging condition

Hydroxypropylated starch was prepared in the same manner as in Example 13, except that the aging was performed at 60 캜 in a sealed state and aged.

Experimental Example

The substitution degree of the hydroxyalkylated polysaccharides prepared in Examples 1 to 13 and Comparative Examples 1 to 12, the reaction efficiency, the uniformity, and the coating state inside the reactor as an index indicating the continuous reaction workability were examined and the results were as follows: Table 1 shows.

In the following Table 1, measurement of MS (Molar Substitution) for confirming the degree of substitution was performed by measuring the content of hydroxypropyl groups according to the modified starch identification method (Korea Food Additives Attachment).

On the other hand, to confirm the homogeneous reaction, the mass was separated, and the mass distribution (%) was determined by measuring the particle size distribution of the raw material and using the 60 mesh standard mass as a percentage of the total mass.

The coating properties (coating state inside the reactor after the reaction) were evaluated as an index indicating the continuous reaction workability. The evaluation of the coating properties was made by visual inspection. The coating state was evaluated according to the coating degree, , And the coating property evaluation score was assigned to each of the following criteria.

- Hardness of the coating layer (hardly scratching the coating layer): 1 point,

- Coat layer is slightly stiff (scrape coating layer slightly hard): 2 points,

- Coat layer is not hard and smooth (can scratch the coating layer): 3 points,

- the coating layer is somewhat fluid (the coating layer can easily be scraped off): 4 points,

- The coating layer is in powder form and fluid (no scratches due to no coating layer): 5 points

division Key reaction conditions Measurement experiment item Remarks Raw material In raw material
moisture
(weight%) Catalyst temperature
(° C) catalyst
%density
ferment
Fairness Degree of substitution
(MS) reaction
efficiency
(%) Mass
Distribution
(weight%) Coating property
(point)
Example 1 corn 9.7 4 34 U 0.74 95 One 4 30 liter reactor Example 2 Guar gum 10.3 4 34 U 0.75 97 0 5 Example 3 corn 8.8 4 34 U 0.75 97 0 5 Example 4 Guar gum 9.2 4 34 U 0.74 95 0 5 Example 5 corn 3.4 4 34 U 0.74 96 0 5 Example 6 Guar gum 4.0 4 34 U 0.76 98 0 5 Example 7 corn 3.4 30 53 U 0.75 96 0 5 Example 8 Guar gum 4.0 30 53 U 0.76 98 0 5 Example 9 corn 3.4 55 65 U 0.74 95 0 5 Example 10 Guar gum 4.0 55 65 U 0.75 97 0 5 Example 11 corn 4.9 25 50 U 0.75 97 0 5 3000 liter reactor, 10 times Example 12 CMT 0.7 2 32 U
(2 캜) 0.75 97 0 5 Example 13 ATS 0.5 65 69 U
(48 ° C) 0.74 95 0 5 Comparative Example 1 corn 11.7 4 34 U 0.68 88 12 3 30 liter reactor Comparative Example 2 Guar gum 11.4 4 34 U 0.69 89 10 3 Comparative Example 3 corn 3.4 61 69 U 0.67 87 13 4 Supersaturation catalyst
(Browning) Comparative Example 4 corn 3.4 30 45 U 0.67 86 17 2 Unsaturated catalyst Comparative Example 5 corn 3.4 4 32 radish No hydroxypropylation reaction occurred. Non-manufacturing Comparative Example 6 Guar gum 4.0 4 32 radish Non-manufacturing Comparative Example 7 corn 11.7 - 70 radish 0.64 83 21 2 Korea Open Special
1999-46174 Comparative Example 8 Guar gum 11.4 - 70 radish 0.67 86 17 3 Comparative Example 9 corn 11.7 - 50 radish 0.61 78 12 3 Korea Open Special
2006-74755 Comparative Example 10 corn 3.4 - 72 U 0.68 88 13 2 Saturated catalyst Comparative Example 11 corn 3.4 - 29 U 0.67 86 22 2 Saturated catalyst Comparative Example 12 ATS 0.5 65 69 U
(60 DEG C) 0.66 85 11 2 High temperature aging
(Browning) - CMT: carboxymethyl tamarind
- ATS: Acid-treated starch

As can be seen from the above Table 1, the hydroxypropyl polysaccharides of Examples 1 to 13 according to the present invention can be produced by using a raw material having a high water content or by using a catalyst which is not a saturated catalyst, Since the degree of substitution (MS) is much higher than that of the hydroxypropyl polysaccharides of Comparative Examples 1 to 12 prepared by a method using a catalyst having a high or low concentration of saturated aqueous solution, the hydroxyalkylated polysaccharide It was confirmed that the degree of substitution was excellent, and that the reaction efficiency was also superior to that of the prior art. In particular, even if the aging process is carried out according to the method of the present invention, it is also confirmed that the substitution and reaction efficiency are significantly lowered when the moisture content of the polysaccharide used as the raw material is too high.

On the other hand, from the viewpoints of the uniformity of the reaction, the hydroxypropyl polysaccharides according to Comparative Examples 1 to 12, which do not undergo the aging process, the prior art, the polysaccharide having a high water content and the inadequate catalyst condition, It was confirmed that the hydroxypropyl polysaccharides of Examples 1 to 13 had very uniform and fine particle distribution with little generation of massive particles.

Therefore, the manufacturing method according to the present invention can dispense with drying, pulverizing and bifurcating processes, which are usually carried out after the reaction, unlike the prior art, thereby remarkably reducing the production facility investment cost of the hydroxyalkyl polysaccharide .

In addition, it is possible to increase the size of the reactor by 3000 L reactor, and to be able to perform the continuous batch reaction without cleaning the inner coating of the reactor since the inside coating state of the reactor is in a fluid state during the reaction, It is possible to solve the troublesome problems such as process interruption and cleaning due to accumulation of coating material at least partly or completely and it has been confirmed that the productivity can be remarkably increased.

It is possible to produce the highly substituted hydroxyalkyl polysaccharides according to the present invention economically and effectively and it is widely used as a sizing agent for the textile industry, a coating agent for the paper industry, a binder for construction materials or adhesive materials, etc. The present invention can be applied to the production process of hydroxyalkyls.

Claims (10)

Preparing a low moisture powder polysaccharide having a moisture content of not more than 11% by weight;
Spraying an alkaline saturated aqueous solution having a concentration of 30 to 70% to the catalyst;
Sealing the mixture in which the catalyst is spray-mixed and aging;
Adding an alkylene oxide to conduct a hydroxyalkylation reaction
Substituted hydroxyalkyl polysaccharides by a dry reaction.
[2] The method according to claim 1, wherein the polysaccharide is one or a mixture of two or more selected from starch, guar gum, tamarind gum, locust bean gum and its modified products or derivatives thereof.
The process for producing a hydroxyalkyl polysaccharide according to claim 1, wherein the catalyst is a saturated aqueous solution of an alkali metal, an alkaline earth metal, oxides and hydroxides thereof, and a water-soluble inorganic salt composed of a strong base and a weak acid.
The process for preparing a hydroxyalkyl polysaccharide according to claim 1, wherein the application temperature of the catalyst is 0 to 70 ° C.
The process for producing a hydroxyalkyl polysaccharide according to claim 1, wherein the aging is carried out at 0 to 50 ° C for 4 hours or more.
The method according to claim 1, wherein the alkylene oxide is used in a ratio of 0.01 to 3.0 mol per unit of anhydroglucose unit contained in the polysaccharide.
The process for preparing a hydroxyalkyl polysaccharide according to claim 1, wherein the hydroxyalkylation reaction is a dry reaction at a temperature of 40 to 120 ° C.
The method according to claim 1 or 7, wherein the hydroxyalkylation reaction is carried out under a closed condition.
The process for producing a hydroxyalkyl polysaccharide according to claim 1, wherein the hydroxyalkylation reaction is not followed by drying, grinding or bifurcation.
The process according to claim 1, wherein each step of the reaction is carried out in a continuous batch reaction.