JP2005171089A - Method for cationized hydroxyalkyl cellulose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially advanced manufacturing method of a cationized hydroxyalkyl cellulose capable of manufacturing effectively and reusing a solvent used in a reaction through recovering by distillation. <P>SOLUTION: This manufacturing method of the cationized hydroxyalkyl cellulose is characterized in that a hydroxyalkyl cellulose and a cationized agent are reacted under existence of a base in a mixed solvent of a 6-10C aliphatic ketone of 50-90 wt%, an 1-3C alcohol of 7-40 wt% and water of 0.5-30 wt%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a cationized hydroxyalkyl cellulose. More specifically, the present invention relates to a method for producing cationized hydroxyalkyl cellulose, which is a semi-synthetic polymer compound that can be suitably used for various applications such as cosmetic raw materials, antistatic agents, flocculants in the papermaking field, and pharmaceuticals.

  As a method for producing cationized hydroxyalkyl cellulose, a method in which hydroxyalkyl cellulose is treated with an alkali and then reacted with a cationizing agent is known (for example, see Patent Document 1). However, this method is economically disadvantageous because hydroxyalkyl cellulose once isolated and purified is used as a raw material.

  On the other hand, cellulose was treated with alkali in a mixed solvent consisting of 85 to 90% by weight of tertiary butanol and 10 to 15% by weight of water to make alkali cellulose, and then reacted with alkylene oxide to give hydroxyalkyl cellulose. A method of producing cationized hydroxyalkyl cellulose by reacting with a cationizing agent in a mixed solvent consisting of 78 to 89% by weight of tertiary butanol and 11 to 22% by weight of water is known (for example, Patent Document 2). reference). However, the mixed solvent of tertiary butanol and water can be recovered by a method such as distillation, but it is inevitable that a large amount of water is mixed in the recovered tertiary butanol. Therefore, when used again as a reaction solvent, the amount of water in the reaction solvent increases and the reaction efficiency decreases, so it is necessary to always replenish new tertiary butanol. There is no such thing.

Japanese Examined Patent Publication No. 59-42681 (page 1, column 2, lines 25-33) JP 62-132901 A (1 page 1 column 2 lines 18)

  An object of the present invention is to provide an industrially advantageous production method capable of efficiently producing cationized hydroxyalkyl cellulose, and further recovering the solvent used in the reaction by distillation or the like and reusing it. To do.

  That is, the present invention comprises hydroxyalkylcellulose and a cationizing agent in the presence of a base, 50 to 90% by weight of an aliphatic ketone having 6 to 10 carbon atoms, 7 to 40% by weight of alcohol having 1 to 3 carbon atoms, and water. The present invention relates to a method for producing a cationized hydroxyalkyl cellulose characterized by reacting in a mixed solvent comprising 0.5 to 30% by weight.

  According to the present invention, cationized hydroxyalkyl cellulose can be efficiently produced. Furthermore, according to the present invention, the solvent used as the reaction solvent can be recovered by distillation or the like and reused, so that cationized hydroxyalkyl cellulose can be advantageously produced industrially.

  The method for producing the hydroxyalkyl cellulose used in the present invention is not particularly limited. For example, there is a method in which alkali cellulose obtained by treating cellulose with an alkaline aqueous solution is mixed with an alkylene oxide and a reaction solvent and subjected to an etherification reaction. preferable.

  More specifically, first, cellulose is treated with an alkaline aqueous solution to produce alkali cellulose.

  Examples of cellulose include sheet-like and powdery cotton linters, wood pulp, and the like.

  Examples of the alkaline aqueous solution include aqueous solutions of alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. In these, since it is cheap, the aqueous solution of sodium hydroxide is preferable. The concentration of the alkaline aqueous solution is usually about 10 to 30% by weight.

  From the viewpoint of improving the fluidity of the slurry, avoiding the local progress of the reaction between the cellulose and the alkali, and improving the volumetric efficiency, the amount of the alkaline aqueous solution used in producing the alkali cellulose is 100%. It is desirable that it is 1000 to 6000 parts by weight, preferably 2000 to 5000 parts by weight with respect to parts by weight.

  Examples of a method for reacting cellulose and an aqueous alkali solution include methods such as immersion and mixing. Specifically, cellulose is immersed in an alkaline aqueous solution, mixed in a container equipped with a stirring blade, usually at a temperature of 20 to 50 ° C. for about 20 minutes to 2 hours, and subjected to an alkali, followed by pressure filtration. And a method of squeezing and removing the aqueous alkaline solution.

  Next, hydroxyalkyl cellulose can be obtained by etherifying the obtained alkali cellulose and alkylene oxide in a reaction solvent.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and the like.

  The amount of alkylene oxide used is determined by the number of moles of the target alkylene oxide added. Usually, the amount of alkylene oxide used is increased with respect to 1 mol of glucose residues in cellulose from the viewpoint of increasing the amount of addition to cellulose and increasing the solubility of hydroxyalkyl cellulose and increasing the yield of hydroxyalkyl cellulose. It is desirable that the amount is 2 to 8 mol, preferably 3 to 7 mol.

  Examples of the etherification reaction solvent include alcohols such as isopropyl alcohol, isobutyl alcohol, tert-butyl alcohol, and isoamyl alcohol; ethers such as dioxane and 1,2-dimethoxyethane; acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like. Examples thereof include ketones. Among these, from the viewpoint of easy solvent recovery and easy reuse, aliphatic ketones having 6 to 10 carbon atoms, particularly methyl isobutyl ketone, used when producing a cationized hydroxyalkyl cellulose described later are preferable.

  The reaction solvent is used in an amount of 20 to 800 parts by weight, preferably 20 to 600 parts by weight, based on 100 parts by weight of alkali cellulose, from the viewpoint of avoiding the alkylene oxide being locally added to the cellulose and increasing the volumetric efficiency. Part is desirable.

  The reaction temperature is usually 30 to 80 ° C., preferably 40 to 40% from the viewpoint of promoting the reaction, shortening the reaction time, avoiding rapid progress of the reaction, and facilitating control of temperature and pressure. It is desirable that it is 60 degreeC. In addition, since reaction time changes with reaction temperature, it cannot determine unconditionally, However, Usually, it is about 1 to 15 hours.

  After completion of the etherification reaction, a washing solution is added to remove impurities such as alkylene glycols by-produced from excess alkali or alkylene oxide.

  As a cleaning liquid, from the viewpoint of efficiently removing alkylene glycols by-produced by excess alkali or alkylene oxide, a specific amount of alcohol having 1 to 3 carbon atoms and a specific amount of alcohol are used as a reaction solvent used in the reaction. A mixed solvent to which water has been added is preferred. The proportion of the alcohol having 1 to 3 carbon atoms in the mixed solvent is usually preferably 20 to 60% by weight. Moreover, it is preferable that the ratio of the water in a mixed solvent is 5 to 30 weight% normally.

  Examples of the alcohol having 1 to 3 carbon atoms include methanol, ethanol, isopropanol, and n-propanol. Among these, methanol is preferable because it is inexpensive.

  The amount of the cleaning liquid used is 3000 to 8000 parts by weight, preferably 4000 to 7000 parts by weight with respect to 100 parts by weight of cellulose from the viewpoint of leaving an appropriate amount of alkali as a catalyst in the cationization reaction of the next step in the hydroxyalkyl cellulose. It is desirable that

  In the crude hydroxyalkyl cellulose thus obtained, 0.1 to 5% by weight of alkali usually remains. In the present invention, in the cationization reaction in the next step, the cationization reaction proceeds efficiently by reacting the crude hydroxyalkyl cellulose in which a trace amount of alkali remains with a cationizing agent in a specific mixed solvent. be able to. In the present invention, isolated and purified hydroxyalkyl cellulose may be used. In that case, in order to efficiently proceed the cationization reaction, the content of alkali in the hydroxyalkyl cellulose is 0.1 to 0.1. What is necessary is just to add an alkali in a mixed solvent so that it may become 5 weight%.

  Cationic hydroxyalkyl cellulose can be obtained by reacting hydroxyalkyl cellulose with a cationizing agent in a mixed solvent in the presence of a base.

  Examples of the base include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. Among these, sodium hydroxide is preferable because it is inexpensive.

  The amount of the base used may be added to the mixed solvent so that the content of the base in the hydroxyalkyl cellulose is 0.1 to 5% by weight. In the present invention, as described above, the base remaining in the crude hydroxyalkyl cellulose may be used.

  As the mixed solvent, a solvent comprising an aliphatic ketone having 6 to 10 carbon atoms, an alcohol having 1 to 3 carbon atoms and water is preferably used. The content of the aliphatic ketone having 6 to 10 carbon atoms in the mixed solvent is 50 to 90% by weight, preferably 60 to 90%, from the viewpoint of suppressing side reactions and dissolving the cationizing agent to allow the reaction to proceed efficiently. The content of the alcohol having 1 to 3 carbon atoms is 7 to 40% by weight, preferably 8 to 30% by weight, and the water content is 0.5 to 30% by weight, preferably 1 -20% by weight.

  Examples of the aliphatic ketone having 6 to 10 carbon atoms include methyl isobutyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, ethyl-n-butyl ketone, di-n-propyl ketone, and diisobutyl ketone. Can do. Among these, methyl isobutyl ketone is preferred from the viewpoint of relatively low boiling point and easy recovery by distillation.

  Examples of the alcohol having 1 to 3 carbon atoms include methanol, ethanol, isopropanol, and n-propanol. Among these, methanol is preferable because it is inexpensive.

  The amount of the mixed solvent used is 900 to 2600 parts by weight with respect to 100 parts by weight of hydroxyalkyl cellulose, preferably from the viewpoint of avoiding local cationization of hydroxyalkyl cellulose and increasing the volumetric efficiency, preferably It is desirable that it is 1100-2500 weight part.

  Examples of the cationizing agent used in the present invention include glycidyltrialkylammonium halides such as glycidyltrimethylammonium chloride, glycidyltriethylammonium chloride, glycidyltrimethylammonium bromide, and glycidyltriethylammonium bromide. Among these, glycidyltrimethylammonium chloride is preferable from the viewpoint of low cost and high reactivity.

  From the viewpoint of increasing the yield of the cationized hydroxyalkyl cellulose and avoiding the inefficiency of the use amount and not being economical, the amount of the cationizing agent used is 1 mol of glucose residue in the cellulose. It is desired to be 0.1 to 1.4 mol, preferably 0.3 to 1.2 mol.

  The reaction temperature is usually 40 to 60 ° C., preferably 45 to 55 ° C., from the viewpoints of promoting the reaction and shortening the reaction time and avoiding the rapid progress of the reaction. In addition, since reaction time changes with reaction temperature, it cannot determine unconditionally, However, Usually, it is about 2 to 4 hours.

  After completion of the cationization reaction, a cationized hydroxyalkyl cellulose can be purified by adding a cleaning solution containing a neutralizing agent and removing excess alkali and salts generated by neutralization.

  Examples of the neutralizing agent include strong acids such as sulfuric acid, hydrochloric acid, and nitric acid, and weak acids such as acetic acid and phosphoric acid. Among these, hydrochloric acid is preferable because it is inexpensive.

  As the cleaning liquid, excess alkali and salts generated by neutralization can be efficiently removed, and from the viewpoint of easy recovery of the solvent, the aliphatic ketone having 6 to 10 carbon atoms is 40 to 50% by weight. A mixed solvent composed of 40 to 50% by weight of alcohol having 1 to 3 carbon atoms and 5 to 15% by weight of water is desirable.

  The amount of the cleaning liquid used is 100 parts by weight of cellulose from the viewpoint of efficiently removing excess alkali and salts generated by neutralization, and from the viewpoint of avoiding an economical effect that is not commensurate with the amount of use. On the other hand, 300 to 2000 parts by weight, preferably 500 to 1900 parts by weight are desirable.

  The cationized hydroxyalkyl cellulose thus obtained can be isolated from the washing solution by a method such as filtration, and then dried under normal pressure or reduced pressure to obtain a dried product.

  The reaction solvent used for the production of cationized hydroxyalkyl cellulose and the solvent used for washing are separated and recovered by distillation. For example, when methyl isobutyl ketone is used as the aliphatic ketone having 6 to 10 carbon atoms, and methanol is used as the alcohol having 1 to 3 carbon atoms, methyl isobutyl ketone, methanol and water are included as the low boiling fraction at 65 to 88 ° C. A fraction is obtained. Moreover, the fraction containing methyl isobutyl ketone and water is obtained as a high boiling fraction of 88-120 degreeC. In particular, methyl isobutyl ketone and water are obtained in an azeotropic composition having a boiling point of 88 ° C. and a methyl isobutyl ketone / water weight ratio of 3/1, and are separated into two layers. Methyl isobutyl ketone and water separated and recovered from the high-boiling fraction can be used again as a reaction solvent or a washing solvent. Further, a fraction containing methyl isobutyl ketone, methanol and water recovered as a low boiling fraction can be used as a washing solvent.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples.

  The remaining amount of sodium hydroxide and the remaining amount of the solvent in the obtained crude hydroxyalkyl cellulose, the degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyalkyl cellulose were determined by the following method. It was evaluated by.

(1) Residual amount of sodium hydroxide in crude hydroxyalkyl cellulose 4.0 g of crude hydroxyalkyl cellulose was precisely weighed, dissolved in 100 g of ion-exchanged water, titrated with 1N hydrochloric acid using phenolphthalein as an indicator, The amount of sodium hydroxide was calculated from the amount of hydrochloric acid used. The amount of crude sodium hydroxide was determined by converting the amount of sodium hydroxide calculated by weight.

(2) Residual amount of solvent in crude hydroxyalkyl cellulose 2.0 g of crude hydroxyalkyl cellulose was extracted with 10.0 g of acetone, and aliphatic ketone A (g) having 6 to 10 carbon atoms and alcohol B (by gas chromatography) g) was quantified. Furthermore, the crude hydroxyalkyl cellulose was dried at 60 ° C. for 5 hours, and the solid content C (g) was measured. From the obtained results, the amount of water was calculated from the following formula.
Amount of water (g) = 2− (A + B + C)

(3) Degree of substitution of cationizing agent When the cationized alkyl cellulose is cationized hydroxyethyl cellulose and the cationizing agent is glycidyltrimethylammonium chloride, the nitrogen content in the cationized hydroxyethyl cellulose is N (%), and cationized hydroxy. Assuming that the number of moles of ethylene oxide added in ethyl cellulose is EO (mol), the molecular weight per glucose unit of hydroxyethyl cellulose is 162 + 44 EO, and the molecular weight of glycidyltrimethylammonium chloride, which is a cationizing agent, is 151.5.
N = [14 × degree of substitution of cationizing agent] × 100 / [162 + 44EO + 151.5 × degree of substitution of cationizing agent]
Therefore, the degree of substitution of the cationizing agent can be determined from the following formula.
Degree of substitution of cationizing agent = [N × (162 + 44EO)] / [1400-151.5 × N]
In addition, ethylene oxide addition mole number EO (mol) and nitrogen content N (%) were calculated | required with the following method.

(I) Ethylene oxide added mole number Hydroxyethyl cellulose was charged into a kneader and neutralized with a 5.6 wt% acetic acid aqueous solution. After neutralization, it was dried at 80 ° C. using a vacuum dryer and pulverized to obtain a hydroxyethylcellulose sample.

  In accordance with Japanese Pharmacopoeia Pharmaceuticals Component Standard 12993, about 0.075 g of hydroxyethyl cellulose obtained by the above method and 5 mL of hydroiodic acid are added to a decomposition flask, and at 60 to 140 ° C. while aeration of carbon dioxide is performed. Thermal decomposition for 90 minutes. The gas generated by decomposition was passed through red phosphorus suspension water and then absorbed in 10 mL of silver nitrate ethanol solution and 15 mL of bromineacetic acid solution.

  The silver nitrate ethanol solution was prepared by dissolving 15 g of silver nitrate in 50 mL of pure water, further adding 400 mL of 95% ethanol, and adding 5 drops of nitric acid thereto. A bromineacetic acid solution was prepared by adding 460 mL of acetic acid and 8 g of potassium bromide to 40 mL of a bromineacetic acid stock solution prepared by adding 25 g of bromine to 500 mL of acetic acid.

Subsequently, the silver nitrate ethanol solution which absorbed the decomposition gas of hydroxyethyl cellulose was titrated with 0.05 mol / L ammonium thiocyanate aqueous solution, and the bromine acetic acid solution was titrated with 0.05 mol / L sodium thiosulfate aqueous solution. A blank test was conducted in the same manner. From the obtained value, the amount (%) of oxyethylene groups was determined from the following formula. The ethylene oxide addition mole number EO (mol) was calculated | required from the value.
Amount of oxyethylene group: F (%) = D + E
However, D = [(c−b) × 1.1013 / a] × 100
E = [(ed) × 2.2026 / a] × 100
Where a: amount of hydroxyethyl cellulose (g)
b: Sodium thiosulfate blank test (mL)
c: Sodium thiosulfate titration (mL)
d: Ammonium thiocyanate blank test (mL)
e: Ammonium thiocyanate titration (mL)
Since the amount (%) of oxyethylene groups corresponds to the weight (%) of ethylene oxide per glucose unit, the following formula is established.
44 EO / (162 + 44 EO) = F / 100
Therefore, ethylene oxide addition mole number EO (mol) can be calculated | required from a following formula.
EO (mol) = [162 × F] / [44 × (100−F)]

(B) Nitrogen content Based on the formulation standard 523040 by cosmetic varieties, cationized hydroxyethyl cellulose was dried at 105 ° C. for 3 hours, about 1 g was weighed and dissolved by adding water to make exactly 1000 mL. Water was added to 5 mL of this solution to make 50 mL, 4 drops of toluidine blue reagent solution was added, and titrated with 0.0025 N potassium polyvinyl sulfate. However, the end point of the titration was when the blue color of the liquid changed to reddish purple. A blank test was conducted in the same manner. The nitrogen content N (%) was determined from the obtained value.
Amount of nitrogen: N (%) = [(g−h) × 70.03] / [f × (100−i)]
Where f: amount of cationized hydroxyethyl cellulose (g)
g: Potassium polyvinyl sulfate titration (mL)
h: Polyvinyl potassium sulfate empty test (mL)
i: [ignition residue (%) / dry residue (%)] × 100 × 0.8229

(4) Light transmittance Sodium alkyl ether sulfate (trade name of Nippon Oil & Fat Co., Ltd .; Persoft EF) 30.89 parts by weight, polyoxyethylene glycol ether methyl glycoside (trade name of Amerchol; GLUCAM E-20) 3 A liquid A consisting of .46 parts by weight and 27.55 parts by weight of water, and B liquid consisting of 0.96 parts by weight of cationized hydroxyethyl cellulose, 1.38 parts by weight of sodium chloride and 35.76 parts by weight of water were prepared. A solution obtained by mixing 61.9 parts by weight of liquid A and 38.1 parts by weight of liquid B until uniform was put into a cell having an optical path length of 10 mm, and transmittance (%) at 425 nm using a spectrophotometer. ) Was measured. In general, if the light transmittance is 80% or more, it can be determined that the transparency is excellent.

Production Example 50 g of finely pulverized wood pulp as cellulose was immersed in 2000 g of a 20 wt% aqueous sodium hydroxide solution, and stirred and mixed at 30 ° C. for 30 minutes in a 5 L flask to allow alkali to act. Then, pressure filtration was carried out and the sodium hydroxide aqueous solution was squeezed and removed to obtain 150 g of alkali cellulose. Into a 1 L kneader, 150 g of the obtained alkali cellulose, 75 g (1.70 mol) of ethylene oxide and 50 g of methyl isobutyl ketone were charged at 15 ° C., and then mixed for 30 minutes at the same temperature. Reacted for hours.

  Next, a mixed solvent consisting of 450 g of methyl isobutyl ketone, 450 g of methanol and 100 g of water was added to the obtained reaction product to form a slurry. The resulting slurry was allowed to stand for several minutes, and then hydroxyethyl cellulose was filtered off. Further, a mixed solvent consisting of 225 g of methyl isobutyl ketone, 225 g of methanol and 50 g of water was added to the filtered hydroxyethyl cellulose to form a slurry, which was separated by filtration in the same manner as described above. This operation was repeated 4 times to obtain 154 g of crude hydroxyethyl cellulose. The amount of hydroxyethyl cellulose in the obtained crude hydroxyethyl cellulose was 75 g, the residual amount of sodium hydroxide was 1.78% by weight, and the residual amount of the solvent was 22 g of methyl isobutyl ketone, 44 g of methanol and 12 g of water.

Example 1
In a 1 L separable flask, 154 g of crude hydroxyethyl cellulose obtained in the same manner as in the preparation example (containing 22 g of methyl isobutyl ketone, 44 g of methanol and 12 g of water, residual amount of sodium hydroxide 1.78% by weight), 578 g of methyl isobutyl ketone Then, 116 g of methanol and 28 g of water were charged, and the reaction solvent was adjusted to 75% by weight of methyl isobutyl ketone, 20% by weight of methanol and 5% by weight of water to prepare a slurry, and then 30 g of glycidyltrimethylammonium chloride was added dropwise.

  After completion of dropping, the reaction was carried out at 50 ° C. for 3 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and the remaining sodium hydroxide was added in a solution of 12 g of a 35 wt% hydrochloric acid aqueous solution in 600 g of a mixed solvent (50 wt% methyl isobutyl ketone, 45 wt% methanol and 5 wt% water). After the addition, filtration was carried out, followed by drying at 60 ° C. for 5 hours to obtain 79.4 g of cationized hydroxyethyl cellulose.

  The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

  On the other hand, the etherification reaction solvent, cationization reaction solvent, and washing solvent were recovered to obtain a mixed solvent of 2278 g of methyl isobutyl ketone, 1736 g of methanol, and 441 g of water. The obtained mixed solvent was distilled to obtain 2130 g of a low-boiling fraction at 65 to 88 ° C and 2258 g of a high-boiling fraction at 88 to 120 ° C. In each composition, the low boiling fraction was composed of 340 g of methyl isobutyl ketone, 1729 g of methanol and 61 g of water, and the high boiling fraction was composed of 1937 g of methyl isobutyl ketone and 321 g of water. The water content in the upper layer methyl isobutyl ketone of the high-boiling fraction was 2% by weight.

Example 2
A mixed solvent having the same composition as the mixed solvent used in Example 1 was prepared using methyl isobutyl ketone distilled and collected as the upper layer of the high-boiling fraction in Example 1, and then in the same manner as in Example 1. Reaction was performed. As a cleaning solution after the reaction, a low-boiling fraction consisting of methyl isobutyl ketone, methanol and water recovered as a low-boiling fraction in Example 1 and methyl isobutyl ketone recovered by distillation were used in combination and used in Example 1. After preparing a mixed solvent having the same composition as the mixed solvent for washing, washing was performed using this mixed solvent to obtain 79.2 g of cationized hydroxyethyl cellulose.

  The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

Example 3
In Example 1, 83.2 g of cationized hydroxyethylcellulose was obtained in the same manner as in Example 1 except that the amount of glycidyltrimethylammonium chloride was changed to 40.3 g.

  The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

Example 4
In Example 1, 85.6 g of cationized hydroxyethylcellulose was obtained in the same manner as in Example 1 except that the amount of glycidyltrimethylammonium chloride was changed to 49.8 g.

  The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

Example 5
In a 1 L separable flask, 154 g of crude hydroxyethyl cellulose obtained in the same manner as in the preparation example (containing 22 g of methyl isobutyl ketone, 44 g of methanol and 12 g of water, 1.78% by weight of sodium hydroxide remaining), 658 g of methyl isobutyl ketone And 68 g of methanol were prepared, and the reaction solvent was adjusted to 85% by weight of methyl isobutyl ketone, 14% by weight of methanol and 1% by weight of water to prepare a slurry, and then 30 g of glycidyltrimethylammonium chloride was added dropwise.

  After completion of dropping, the reaction was carried out at 50 ° C. for 3 hours. After the completion of the reaction, 85.6 g of cationized hydroxyethyl cellulose was obtained in the same manner as in Example 1. The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

Example 6
In a 1 L separable flask, 154 g of crude hydroxyethyl cellulose obtained in the same manner as in the preparation example (containing 22 g of methyl isobutyl ketone, 44 g of methanol and 12 g of water, residual amount of sodium hydroxide 1.78% by weight), 498 g of methyl isobutyl ketone Then, 156 g of methanol and 68 g of water were charged, and the reaction solvent was adjusted to 65% by weight of methyl isobutyl ketone, 25% by weight of methanol and 10% by weight of water to prepare a slurry, and then 30 g of glycidyltrimethylammonium chloride was added dropwise.

  After completion of dropping, the reaction was carried out at 50 ° C. for 3 hours. After completion of the reaction, 89.2 g of cationized hydroxyethyl cellulose was obtained in the same manner as in Example 1. The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

Comparative Example 1
In a 1 L separable flask, 154 g of crude hydroxyethyl cellulose obtained in the same manner as in the preparation example (containing 22 g of methyl isobutyl ketone, 44 g of methanol and 12 g of water, residual amount of sodium hydroxide 1.78% by weight), and methyl isobutyl ketone 722 g was charged, and the reaction solvent was adjusted to 93% by weight of methyl isobutyl ketone, 5% by weight of methanol and 2% by weight of water to prepare a slurry, and then 30 g of glycidyltrimethylammonium chloride was added dropwise.

  After completion of dropping, the reaction was carried out at 50 ° C. for 3 hours. After completion of the reaction, 99.8 g of cationized hydroxyethyl cellulose was obtained in the same manner as in Example 1. The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

Comparative Example 2
In a 1 L separable flask, 154 g of crude hydroxyethyl cellulose obtained in the same manner as in the production example (containing 22 g of methyl isobutyl ketone, 44 g of methanol and 12 g of water, 1.78% by weight of sodium hydroxide remaining), 400 g of methyl isobutyl ketone Then, 360 g of methanol and 40 g of water were charged, and the reaction solvent was adjusted to 50% by weight of methyl isobutyl ketone, 45% by weight of methanol and 5% by weight of water to prepare a slurry, and then 30 g of glycidyltrimethylammonium chloride was added dropwise.

  After completion of dropping, the reaction was carried out at 50 ° C. for 3 hours. After completion of the reaction, 80.4 g of cationized hydroxyethyl cellulose was obtained in the same manner as in Example 1. The degree of substitution of the cationizing agent and the light transmittance of the obtained cationized hydroxyethyl cellulose were measured by the above methods. The results are shown in Table 1.

  In Table 1, MIBK represents methyl isobutyl ketone, and MeOH represents methanol.

From the results shown in Table 1, the cationized hydroxyethyl cellulose obtained in Examples 1 to 6 is excellent in transparency because the reaction between hydroxyethyl cellulose and the cationizing agent proceeds uniformly. On the other hand, in the cationized hydroxyethyl cellulose obtained in Comparative Example 1, the reaction between the hydroxyethyl cellulose and the cationizing agent proceeds non-uniformly and the transparency is deteriorated. Moreover, although the cationized hydroxyethylcellulose obtained by the comparative example 2 is excellent in transparency, it turns out that reaction with hydroxyethylcellulose and a cationizing agent has hardly progressed.

Claims (4)

  Hydroxyalkyl cellulose and a cationizing agent in the presence of a base, 50 to 90% by weight of an aliphatic ketone having 6 to 10 carbon atoms, 7 to 40% by weight of alcohol having 1 to 3 carbon atoms, and 0.5 to 30% of water %. A method for producing a cationized hydroxyalkyl cellulose, wherein the reaction is carried out in a mixed solvent comprising 1%.   The method for producing a cationized hydroxyalkyl cellulose according to claim 1, wherein the aliphatic ketone having 6 to 10 carbon atoms is methyl isobutyl ketone.   The method for producing a cationized hydroxyalkyl cellulose according to claim 1 or 2, wherein the alcohol having 1 to 3 carbon atoms is methanol. The method for producing a cationized hydroxyalkyl cellulose according to any one of claims 1 to 3, wherein the cationizing agent is glycidyltrimethylammonium chloride.