JPH0725903A - Method for producing high-purity cationized pullulan - Google Patents

Abstract

PURPOSE:To obtain a high purity cationized pullulan not containing residual organic solvent, by eliminating a residual cationizing agent, reaction byproducts and salts at a low cost with an ultrafiltration. CONSTITUTION:To obtain a high purity cationized pullulan, purified by a ultrafiltration method using a ultrafiltration membrane to remove a residual cationizing agent, reaction byproducts derived thereby and salts to an extent that the concentration of each of the above contaminants is 0.5% or less against the polymer. The pores of the ultrafiltration membrane prohibit the pass of the material with a molecular weight of 50,000 or more. The pullulan is reacted with a cationizing agent selected from the compounds of the formula I and II (where R1 to R3 are a hydrocarbon; X, Y are a halogen) to give the cationized pullulan. In this reaction the amount of the cationizing agent used to react is in a molar ratio of 0.1 against the anhydrous glucose units in the pulluran.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing high-purity cationized pullulan.

[0002]

2. Description of the Prior Art Cationized pullulan is a compound having a quaternary ammonium salt as a substituent and has been widely used for various cosmetic additives, fiber treating agents, paper treating agents and the like.

Cationized pullulan is produced by cationizing raw material pullulan. Unreacted cationizing agents and alkalis and impurities derived therefrom are impurities that may be mixed during cationization. Reaction by-products may be mentioned. In the conventional method for producing cationized pullulan, a nonsolvent of cationized pullulan is added and mixed to crystallize and collect as a refining means for improving the purity, followed by re-dissolving in water and recrystallization. The method of washing was repeated. As a solvent for this purpose, for example, lower alcohols such as methanol, ethanol and isopropanol alone or a mixed solvent with acetone, tetrahydrofuran, dioxane and the like have been used.

[0004]

However, in the purification method using these organic solvents, the inorganic salts such as Na salts derived from the alkaline substance used in the reaction have low solubility in the organic solvent and cannot be sufficiently removed. Repeated operations 3 to 6 times of water dissolution and organic solvent crystallization leave unreacted cationic agent and reaction by-products derived therefrom at about 1% by weight with respect to the polymer, and 10 times or more to further reduce the content. Therefore, there has been a problem that a large amount of solvent and complicated operation are required. Further, there is a problem of cost increase due to steam cost and the like for distilling and collecting the used solvent.

Further, since the organic solvent is used, there is a problem that it remains in the product, and it is technically difficult to lower the residual solvent. Therefore, if it is toxic like methanol, it is used in cosmetics. At that time, there was a problem that the residual amount was strictly regulated and the application range was limited.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention provides
In view of the above circumstances, it is possible to easily and inexpensively remove impurities from unpurified cationized pullulan, and solve the problem of residual organic solvent, and the gist thereof is unpurified cation. This is a method for producing high-purity cationized pullulan in which purified pullulan is purified by an ultrafiltration method using an ultrafiltration membrane.

The cationized pullulan to be purified in the present invention is obtained by reacting the raw material pullulan and the cationizing agent in the presence of water and an alkaline substance.

The raw material pullulan is a linear polymer natural polysaccharide in which maltotriose, which is a trimer of glucose, is repeatedly linked by α-1,6 bond which is a bond different from the trimer. is there. This raw material pullulan is, for example, a type of black yeast, Aureobasidium pullulans, which is cultivated under appropriate conditions using sucrose or a starch decomposition product as a carbon source, and the viscosity produced in the culture solution. It can be obtained as a polysaccharide and is used in the food field, cosmetic field, and industrial field. Although the physical properties of the produced pullulan are slightly different depending on the kind of the strain to be used, any grade can be used in the present invention.

The cationizing agent is represented by the general formula (I)
[In Formula (I), R₁, R₂, R ₃Is a hydrocarbon group, X
Is a halogen atom]
Lutrialkylammonium halide (glycidyl tri
Alkylammonium salt) and general formula (II) [formula (I
R in I)₁, R₂, R₃Is a hydrocarbon group, X and Y are
Halogen atom] represented by 3-halogeno-2hydroxy
There is a propyltrialkylammonium halide. Or
These cationizing agents may be used alone or in combination of two or more.
It can also be used in combination.

[0010]

[Chemical 3]

[Chemical 4]

R in the above formula₁, R₂, R₃Hydrocarbon group of
Is not only a chain or branched alkyl group, but
It can be a Japanese hydrocarbon group or an aromatic hydrocarbon group.
However, R in the above formula₁, R₂Is an alky having 1 to 3 carbon atoms
Preferably a R group, R ₃Is a C1-18
It is preferably a rukyl group. Also, as X and Y
Chlorine is preferred among chlorine, iodine, and iodine.
Good

As specific examples of the cationizing agent, glycidyltrimethylammonium chloride, glycidyltriethylammonium chloride,
Examples thereof include glycidyltripropylammonium chloride, glycidyldimethyloctylammonium chloride, glycidyldimethyldecylammonium chloride, glycidyldimethyllaurylammonium chloride and glycidyldimethylstearylammonium chloride.
Further, regarding the formula (II), 3-chloro-2hydroxypropyltrimethylammonium chloride, 3-chloro-
2-hydroxypropyltriethylammonium chloride, 3-chloro-2hydroxypropyltripropylammonium chloride, 3-chloro-2hydroxypropyldimethyloctylammonium chloride, 3-chloro-2hydroxypropyldimethyldecylammonium chloride, 3-chloro-2hydroxypropyl Examples thereof include dimethyllauryl ammonium chloride and 3-chloro-2hydroxypropyl dimethylstearyl ammonium chloride.

The amount of the above cationizing agent added is arbitrarily selected according to the desired degree of cation modification, but it is preferably 0.1 times or more the molar ratio of the raw material pullulan per anhydroglucose unit.

The amount of water added during the reaction is preferably 2 in terms of molar ratio per unit of anhydrous glucose of pullulan as a raw material.
˜80 times, more preferably 5 to 40 times the molar ratio per anhydroglucose unit.

As the alkaline substance, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide can be used. Of these, preferred is sodium hydroxide.

The alkaline substance is added preferably in a molar ratio of 0.000 per anhydrous glucose unit of the raw material pullulan.
It is 1 to 1.0 times.

The reaction temperature is preferably 40 to 80 ° C.

In the present invention, after completion of the cationization reaction, the catalyst alkaline substance is neutralized with a mineral acid or an organic acid, and then water is added to the cationized pullulan to dissolve it.
This is ultrafiltered.

In carrying out the ultrafiltration, the cationized pullulan concentration is advantageously between 1 and 250 g / l, preferably between 5 and 150 g / l.

In the method for producing high-purity cationized pullulan according to the present invention, a known ultrafiltration device can be used.

In the present invention, one of the conditions is to use a porous membrane having pores that are small enough to prevent the passage of cationized pullulan. In the present invention, approximately 100,000 to
Since a cationized pullulan having a molecular weight of 10 million is targeted, a porous membrane having a cut-off molecular weight of 50,000, preferably 10,000 or less, is used.

As the membrane material of the porous membrane, commercially available polysulfone, polyvinylidene fluoride, cellulose acetate and the like can be mentioned. In the present invention, any of them can be used, and a specific material can be used. It is not limited to. The ultrafiltration membrane modules that can be used include flat membrane, tubular, spiral,
All of the horofibers are targeted.

The pH during ultrafiltration is preferably 4
And the temperature is 5 to 60 ° C., preferably 15 to 5
It is 0 ° C.

When an unpurified aqueous solution of cationized pullulan is subjected to ultrafiltration, impurities pass through the ultrafiltration membrane (porous membrane) together with water, and a high purity is obtained in the residue that has not passed through the ultrafiltration membrane. The cationized pullulan of the above is concentrated. The high-purity cationized pullulan thus obtained is
In addition to being used in the form of an aqueous solution, it may be dried and solidified according to the purpose.

[0025]

EXAMPLES Examples 1 to 3 and Comparative Examples 1 and 2 will be shown below, but the present invention is not limited to these Examples.

Example 1 50 parts by weight of an aqueous solution containing 40 parts by weight of glycidyltrimethylammonium chloride and 67 parts by weight of water were put into a kneader with a condenser and mixed, and 100 parts by weight of pullulan (average molecular weight 200,000) was added thereto. And mixed at room temperature until uniform. To this slurry, 10 parts by weight of a 13% aqueous sodium hydroxide solution was added, the temperature was raised to 50 ° C., and the mixture was mixed and reacted at this temperature for 3 hours. Next, 2 parts by weight of acetic acid was added to neutralize the mixture, and then water 2,0 was added.
00 parts by weight was added to dilute and dissolve the polymer to a polymer concentration of 6%. This cationized pullulan-containing aqueous solution was treated at room temperature with an ultrafiltration membrane (flat membrane module, polysulfone) having a molecular weight cut off of 10,000, and the liquid was removed until the nitrogen content of solids in the residue did not decrease. Transparent. The total amount of permeated liquid was 1,500 parts by weight. The residue was dried at 60 ° C. to obtain 125 parts by weight of cationized pullulan. The cationized pullulan obtained had a nitrogen content of 2.1% and a degree of cationization per anhydroglucose unit of 0.3. The amount of unreacted cationizing agent in this cationized pullulan (including reaction by-products), ignition residue and viscosity of 10% aqueous solution, light transmittance, and yellowness were obtained in Examples 2 to 3 and Comparative Examples described later. The cationized pullulan thus obtained is shown in Table 1. It was found that there were few impurities such as ignition residue, the transparency was excellent, and the degree of coloring was low.

Example 2 The reaction neutralized product obtained by the reaction under the same conditions as in Example 1 was dissolved in 1,000 parts by weight of water and subjected to ultrafiltration. The same ultrafiltration membrane as in Example 1 was used, and the treatment was performed at room temperature. The liquid was permeated by 500 parts by weight, 500 parts by weight of water was added to the residue, and filtration was performed again to permeate the liquid by 500 parts by weight. The residue was treated again with 500 parts by weight of water to allow 500 parts by weight of the liquid to permeate. The nitrogen content of solids in the residue was the same as in Example 1. The residue was dried at 60 ° C. to obtain 125 parts by weight of cationized pullulan. The cationized pullulan obtained had a nitrogen content of 2.1% and a degree of cationization per anhydroglucose unit of 0.3.

Example 3 100 parts by weight of an aqueous solution containing 80 parts by weight of glycidyltrimethylammonium chloride and 57 parts by weight of water were put into a kneader equipped with a condenser and mixed, and 100 parts by weight of pullulan was added thereto to make the mixture uniform. And mixed at room temperature. To this slurry, 10 parts by weight of 13% aqueous sodium hydroxide solution was added, the temperature was raised to 50 ° C., and the mixture was mixed at this temperature for 5 hours. Next, 2 parts by weight of acetic acid was added to neutralize, and then 3,500 parts by weight of water was added to dissolve. This cationized pullulan-containing aqueous solution had a molecular weight cut-off of 1
Treatment was carried out at room temperature with an ultrafiltration membrane (flat membrane module, polysulfone), and the liquid was allowed to permeate until the nitrogen content of solids in the residue did not decrease. Total permeate volume is 3,
It was 000 parts by weight. The residue was dried at 60 ° C. to obtain 150 parts by weight of cationized pullulan. The cationized pullulan obtained had a nitrogen content of 3.5% and a degree of cationization per anhydroglucose unit of 0.65.

Comparative Example 1 The reaction neutralized product obtained by the reaction under the same conditions as in Example 1 was added to acetone / methanol (W
/ R) = 1 / 1,600 parts by weight was added and mixed to crystallize the reaction product. After re-dissolving the crystallization cake in water, acetone / methanol (W / R) = 1 / 1,6 again
It was recrystallized at 00 parts by weight. By the time the nitrogen content of the solids in the crystallization cake does not decrease, these redissolved,
The recrystallization had to be repeated three more times. It was dried at 60 ° C. to obtain 124 parts by weight of cationized pullulan. The cationized pullulan obtained had a nitrogen content of 2.1% and a degree of cationization per anhydroglucose unit of 0.3.

Comparative Example 2 The reaction neutralized product obtained by the reaction under the same conditions as in Example 3 was added to acetone / methanol (W
/ R) = 1 / 1,600 parts by weight was added and mixed to crystallize the reaction product. After re-dissolving the crystallization cake in water, acetone / methanol (W / R) = 1 / 1,6 again
It was recrystallized at 00 parts by weight. By the time the nitrogen content of the solids in the crystallization cake does not decrease, these redissolved,
The recrystallization had to be repeated three more times. It was dried at 60 ° C. to obtain 147 parts by weight of cationized pullulan. The cationized pullulan obtained had a nitrogen content of 3.5% and a degree of cationization per anhydroglucose unit of 0.65.
Met.

[0031]

[Table 1]

As can be understood from the above Examples 1 to 3 and Comparative Examples 1 and 2, the present invention can easily remove water-soluble low-molecular impurities. Further, the obtained cationized pullulan has a smaller amount of ignition residue derived from an inorganic salt and a lower yellowness value measured by a color computer, as compared with those purified by using an organic solvent.
This means that the concentration of inorganic salts such as Na salt could be remarkably reduced, and the coloring substance during the reaction could be removed at the same time.

[0033]

As is apparent from the above, according to the present invention, it is possible to easily remove water-soluble low-molecular impurities, and also to significantly reduce the concentration of inorganic salts such as Na salts. It is possible to obtain highly pure cationized pullulan. Further, since the coloring substance in the reaction can be removed at the same time by ultrafiltration, there is an advantage that a product having a low degree of coloring can be obtained.

In the conventional method using an organic solvent, all of the equipment are required to have an explosion-proof property, and a digestion equipment and the like are also required. In the present invention, by not using an organic solvent,
The equipment cost can be significantly reduced. In particular, since the step of distilling and collecting the organic solvent is eliminated, the cost can be reduced by simplifying the step and eliminating the need for steam cost and the like. Furthermore, there is no problem of residual organic solvent, and a wide range of applications are expected. In addition, the working environment has been improved and the advantages in industrialization are great.

Front Page Continuation (72) Inventor Mitsuo Narita 28, Nishi-Fukushima, Chubiki-mura, Nakakubiki-gun, Niigata Prefecture 1 Shin-Etsu Chemical Co., Ltd.

Claims (4)

[Claims] 1. An ultrafiltration method using an ultrafiltration membrane,
A high-purity cationized pullulan characterized by removing unreacted cationizing agent, reaction by-products derived from it, and salts, and purifying each to a concentration of 0.5% by weight or less based on the polymer. Production method. 2. The method for producing high-purity cationized pullulan according to claim 1, wherein the pores of the ultrafiltration membrane prevent the passage of those having a molecular weight of 50,000 or more. 3. Cationized pullulan is a compound represented by pullulan and a compound represented by the general formula (I) or a compound represented by the general formula (II): [Chemical 2] [In the above general formulas (I) and (II), R ₁ , R ₂ , R ₃
Is a hydrocarbon group, and X and Y are halogen atoms] and is obtained by reacting with at least one or more cationizing agents selected from the group consisting of a high-purity cation according to claim 1. Method for producing activated pullulan. 4. The cationized pullulan is obtained by reacting a cationizing agent with a starting material pullulan at a molar ratio of 0.1 times or more per anhydrous glucose unit. Method for producing high-purity cationized pullulan.