JP2020147678A - Method for producing cellulose derivative - Google Patents

Abstract

To provide a method for producing a cellulose derivative including the step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether, whereby it is possible to efficiently produce a cellulose derivative.SOLUTION: A method for producing cellulose derivative includes the step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether in a solvent in the presence of a basic compound. The solvent is such that a solubility of the hydroxyalkyl cellulose is 0.7 or less at 20°C.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a cellulose derivative.

Cellulose derivatives are used as compounding ingredients in cleaning composition and the like, and their uses are wide-ranging.
For example, in Patent Document 1, as a useful agent as a finishing agent for washing, a part or all of hydrogen atoms of the hydroxy group of the polysaccharide or its derivative are the following groups (A), (B) and (C). Cellulose derivatives substituted with are described.
(A) A linear or branched alkyl group having 10 to 43 carbon atoms, which may be substituted with a hydroxy group and may have an oxycarbonyl group (-COO- or -OCO-) or an ether bond inserted. Alkyl group or acyl group (B) Carboxymethyl group or salt thereof (C) Specific cation group

It is an object of Patent Document 2 to provide an aqueous hair cleaning agent which is excellent in slipperiness of hair at the time of washing and rinsing even if it is damaged hair and can give a moist feeling to the hair after drying. Described as an aqueous hair cleansing agent containing the following components (A), (B) and (C) and water and having a pH of 2 or more and 6 or less at 25 ° C. when diluted 20% by mass with water. Has been done.
(A) Anionic surfactant (B) It has a main chain derived from anhydroglucose, and the degree of substitution of the cationized oxyalkylene group per anhydroglucose unit is 0.01 or more and 1.0 or less, and the glycerol group. A cationic group-containing cellulose ether having a degree of substitution of 0.5 or more and 5.0 or less and a degree of substitution of a group containing a hydrocarbon group having 3 or more and 18 or less carbon atoms of 0 or more and 0.2 or less ( C) Monoalkyl glyceryl ether or monoalkenyl glyceryl ether having an alkyl group or alkenyl group having 4 or more and 12 or less carbon atoms.

Japanese Unexamined Patent Publication No. 2000-178303 Japanese Unexamined Patent Publication No. 2015-168666

Cellulose derivatives are used as compounding ingredients in cleaning agent compositions and the like, but there is a demand for a method for more efficiently producing cellulose derivatives.
The present invention relates to a method for producing a cellulose derivative, which can efficiently produce a cellulose derivative in a method for producing a cellulose derivative, which comprises a step of reacting hydroxyalkyl cellulose with an alkyl glycidyl ether.

The present inventors have found that the above-mentioned problems can be solved by using a solvent having a specific solubility (20 ° C.) of hydroxyalkyl cellulose as the solvent used in the production. It was also found that the above method improves the alkylation selectivity.

That is, the present invention relates to the following [1] and [2].
[1] A solvent having a step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether in the presence of a basic compound in a solvent, wherein the solvent has a solubility of the hydroxyalkyl cellulose at 20 ° C. of 0.7 or less. A method for producing a cellulose derivative.
[2] A step of reacting hydroxyalkyl cellulose with an alkyl glycidyl ether in the presence of a basic compound in a solvent to obtain an alkylated hydroxyalkyl cellulose, wherein the solvent is the hydroxyalkyl cellulose at 20 ° C. A method for improving the alkylation selectivity with respect to hydroxyalkyl cellulose, which is a solvent having a solubility of 0.7 or less.

According to the present invention, there is provided a method for producing a cellulose derivative, which can efficiently produce a cellulose derivative in a method for producing a cellulose derivative, which comprises a step of reacting hydroxyalkyl cellulose with an alkyl glycidyl ether.

[Method for producing cellulose derivatives]
The method for producing a cellulose derivative of the present invention includes a step of reacting hydroxyalkyl cellulose with an alkyl glycidyl ether in the presence of a basic compound (hereinafter, also referred to as “step 1”) in a solvent, and the solvent. However, the hydroxyalkyl cellulose is a solvent having a solubility of 0.7 or less at 20 ° C.
According to the present invention, it is possible to suppress aggregation during production, increase the selectivity of alkylation, and efficiently produce a cellulose derivative.

In the production of a cellulose derivative by reacting hydroxyalkyl cellulose with an alkyl glycidyl ether in the presence of a basic compound in a solvent, the present inventors can efficiently produce the cellulose derivative. I found that it can be difficult.
The present inventors have found that by using a specific solvent, aggregation is suppressed and the alkylation selectivity is improved. This makes it possible to efficiently produce a cellulose derivative.
The detailed mechanism is unknown, but it is inferred as follows. That is, in the above production method, the hydroxyalkyl cellulose is not completely dissolved, but the reaction proceeds in a state where the hydroxyalkyl cellulose is dispersed in a solvent. Here, if the solubility in a solvent is high, it is considered that the surface of the hydroxyalkyl cellulose is excessively dissolved and adheres to each other to cause aggregation.
In the present invention, it is presumed that by using a solvent having a solubility of hydroxyalkyl cellulose at 20 ° C. of 0.7 or less, the dissolution of the above-mentioned hydroxyalkyl cellulose surface is suppressed and the occurrence of aggregation is suppressed. Further, it is considered that the alkylation selectivity was improved by suppressing the occurrence of aggregation.
Hereinafter, each component used in the production method of the present invention, each step, and the like will be sequentially described.

<Step 1>
In the method for producing a cellulose derivative of the present invention, step 1 is a step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether in the presence of a basic compound in a solvent.
Each component used in step 1 will be described.

(Hydroxyalkyl cellulose)
Examples of the hydroxyalkyl cellulose used in the present invention include hydroxyethyl cellulose and hydroxypropyl cellulose, and hydroxyethyl cellulose, hydroxypropyl cellulose, and more preferably hydroxyethyl cellulose.

[Hydroxyalkyl group]
In the present invention, the hydroxyalkyl cellulose has a hydroxyalkyl group introduced into the cellulose. The hydroxyalkyl group is preferably at least one selected from a hydroxyethyl group and a hydroxypropyl group, more preferably having only a hydroxyethyl group or a hydroxypropyl group, and further having only a hydroxyethyl group. preferable. That is, the hydroxyalkyl cellulose may have both a hydroxyethyl group and a hydroxypropyl group, preferably having only one of them, and more preferably having only a hydroxyethyl group.
The degree of substitution of the hydroxyalkyl group is preferably 0.1 or more, more preferably 0.5 or more, still more preferably 1.5 or more, and further, from the viewpoint of the solubility of the hydroxyalkyl cellulose and the obtained cellulose derivative in water. It is preferably 2 or more. Then, from the viewpoint of sufficiently ensuring the fluidity of the cleaning agent composition containing the cellulose derivative (hereinafter, also referred to as the formulation fluidity of the cellulose derivative), it is preferably 10 or less, more preferably 8 or less, still more preferably 5 or less. , More preferably 3 or less.
The degree of substitution of the hydroxyalkyl group is, for example, the degree of substitution of either group when it has only a hydroxyethyl group or a hydroxypropyl group. On the other hand, when it has both a hydroxyethyl group and a hydroxypropyl group, it is the total of the degree of substitution of the hydroxyethyl group and the degree of substitution of the hydroxypropyl group.
In the present invention, the degree of substitution of X groups is the degree of molar average substitution (MS) of X groups, and the average number of moles of substitution of X groups per 1 mol of the constituent monosaccharide units constituting the cellulose derivative or the main chain of cellulose. Means. For example, when the hydroxyalkyl cellulose is hydroxyethyl cellulose, the "degree of substitution of hydroxyethyl groups" means the average number of moles of hydroxyethyl groups introduced (bonded) to 1 mol of anhydroglucose unit. To do.

[Weight average molecular weight]
In the present invention, the weight average molecular weight of hydroxyalkyl cellulose is preferably 1.5 million or less from the viewpoint of sufficiently ensuring solubility in a solvent, reactivity with alkyl glycidyl ether, and formulation fluidity of the obtained cellulose derivative. , More preferably 1.2 million or less, still more preferably 1 million or less, still more preferably 740,000 or less, still more preferably 720,000 or less, still more preferably 600,000 or less, still more preferably 500,000 or less, still more preferably 400,000 or less. It is more preferably 300,000 or less, still more preferably 200,000 or less, and preferably 10,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, still more preferably 100,000 or more.
The weight average molecular weight of the hydroxyalkylated polysaccharide is measured by the method described in Examples.

As the hydroxyalkyl cellulose is commercially available, hydroxyalkyl cellulose obtained from the market may be used.
Specifically, examples of hydroxyethyl cellulose include the Nanosol series (Ashland). Hydroxyethyl cellulose and hydroxypropyl cellulose are also available from Shin-Etsu Chemical Co., Ltd., Dow Chemical Co., Ltd., Nippon Soda Co., Ltd., Sumitomo Seika Chemical Co., Ltd., Sansho Co., Ltd., Daicel Fine Chem Ltd., Tokyo Chemical Industry Co., Ltd. and the like.

(Alkylation glycidyl ether)
The alkylglycidyl ether used in the production of the cellulose derivative of the present invention can introduce an alkyl group into hydroxyalkyl cellulose. Further, the alkylglycidyl ether preferably does not have a cationic group.
Here, the alkyl group introduced into the hydroxyalkyl cellulose is preferably a linear or branched alkyl group, and more preferably a linear alkyl group.
The number of carbon atoms of the alkyl group introduced into the hydroxyalkyl cellulose is preferably 4 or more, more preferably 6 or more, still more preferably 8 or more, still more preferably 10 or more from the viewpoint of imparting hydrophobicity to the hydroxyalkyl cellulose. From the viewpoint of ensuring the solubility of the cellulose derivative, it is preferably 20 or less, more preferably 18 or less, still more preferably 16 or less, still more preferably 15 or less, still more preferably 14 or less.
In the present invention, the alkyl glycidyl ether is preferably a compound represented by the following formula (1).

In formula (1), R represents an alkyl group having 4 or more carbon atoms and 20 or less carbon atoms, R ¹¹ independently represents an alkylene group having 2 to 4 carbon atoms, and n1 is the average number of moles of added −R ¹¹ O−. Is shown, and n1 is 0 or more and 30 or less.

In the formula (1), the number of carbon atoms of the alkyl group represented by R is preferably 4 or more, preferably 6 or more, more preferably 8 or more, and further preferably 10 or more from the viewpoint of imparting hydrophobicity to the hydroxyalkyl cellulose. Yes, and from the viewpoint of ensuring the solubility of the cellulose derivative, it is preferably 20 or less, more preferably 18 or less, still more preferably 16 or less, still more preferably 15 or less, still more preferably 14 or less. The alkyl group may be linear or branched, but is preferably linear.
In the formula (1), R ¹¹ independently represents an alkylene group having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, that is, an ethylene group or a propylene group. If R ¹¹ there are a plurality, may each be the same or different. n1 is 0 or more and 30 or less, preferably 0 or more and 20 or less, more preferably 0 or more and 10 or less, still more preferably 0 or more and 5 or less, and may be 0.

Specific examples of the compound represented by the formula (1) include butyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, nonyl glycidyl ether, decyl glycidyl ether, undecyl glycidyl ether, and dodecyl. Examples thereof include glycidyl ethers having an alkyl group such as glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, pentadecyl glycidyl ether, hexadecyl glycidyl ether, heptadecyl glycidyl ether and octadecyl glycidyl ether.

The amount of alkyl glycidyl ether to be used may be appropriately selected in consideration of the desired degree of substitution (MS _R ) of the alkyl group and the reaction yield, but from the viewpoint of hydrophobically modifying hydroxyalkyl cellulose, hydroxyalkyl Constituent of cellulose The content is preferably 0.001 mol or more, more preferably 0.003 mol or more, still more preferably 0.01 mol or more, and the ease of production of the cellulose derivative and selection of alkylation with respect to 1 mol of the monosaccharide unit. From the viewpoint of increasing the rate, it is preferably 5 mol or less, more preferably 3 mol or less, further preferably 1 mol or less, still more preferably 0.5 mol or less, still more preferably 0.3 mol or less, still more preferably 0.1 mol. It is as follows.
The method of adding the alkylglycidyl ether may be batch, intermittent, or continuous.

(Basic compound)
In the present invention, the reaction between hydroxyalkyl cellulose and alkyl glycidyl ether is carried out in the presence of a basic compound.
Examples of the basic compound include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; and tertiary amines such as trimethylamine and triethylamine. Examples include compounds. Among these, from the viewpoint of the reaction rate with alkyl glycidyl ether, preferably alkali metal hydroxide, alkaline earth metal hydroxide, more preferably alkali metal hydroxide, still more preferably sodium hydroxide and potassium hydroxide. Is. These basic compounds can be used alone or in combination of two or more.
The method of adding the basic compound is not particularly limited, and it may be added all at once or in divided amounts. Further, the basic compound may be added in a solid state or may be added after being made into an aqueous solution.

The amount of basic compound to be added is preferably 0.01 molar equivalent per 1 mol of anhydroglucose unit (AGU) of hydroxyalkyl cellulose from the viewpoint of obtaining sufficient reactivity and increasing alkylation selectivity. The above is more preferably 0.05 molar equivalent or more, still more preferably 0.1 molar equivalent or more, and from the same viewpoint, preferably 10 molar equivalent or less, more preferably 5 molar equivalent or less, still more preferably 3 molar equivalent. Hereinafter, it is more preferably 2 molar equivalents or less, still more preferably 1 molar equivalent or less.

(solvent)
In the present invention, in step 1, hydroxyalkyl cellulose is reacted with alkyl glycidyl ether in the presence of a basic compound in a solvent.
The solvent is a solvent having a solubility of hydroxyalkyl cellulose at 20 ° C. of 0.7 or less.
Here, the solubility of hydroxyalkyl cellulose at 20 ° C. is evaluated with a composition containing hydroxyalkyl cellulose, a basic compound, and a solvent before addition of alkylglycidyl ether.
After stirring the composition, the obtained suspension is centrifuged and the supernatant is extracted. The steps from stirring to extracting the supernatant are performed at 20 ° C. The solubility is calculated by drying the extracted supernatant under reduced pressure in a vacuum dryer and weighing the mass after drying. Solubility is expressed by the following formula.
Solubility = Solids after drying of supernatant (g) ÷ (Amount of supernatant extracted (g) -Solid after drying of supernatant (g)) x 100
Most of the basic compounds are distributed in hydroxyalkyl cellulose, and the amount of the basic compounds present in the supernatant is very small.

The solubility is 0.7 or less, preferably 0.65 or less, more preferably 0.6 or less, still more preferably 0.5 or less, from the viewpoint of suppressing aggregation of hydroxyalkyl cellulose and improving alkylation selectivity. , More preferably 0.45 or less, and from the viewpoint of obtaining reactivity with alkyl glycidyl ether, preferably 0.1 or more, more preferably 0.15 or more, still more preferably 0.2 or more, still more preferable. Is 0.3 or more, more preferably 0.35 or more.

Examples of the solvent to be used include water and a non-aqueous solvent, and a mixed solvent of water and a non-aqueous solvent is preferable.
As the non-aqueous solvent, commonly used alcohols (lower alcohols) having 1 to 4 carbon atoms of primary, secondary or tertiary such as methanol, ethanol, isopropanol and tert-butanol; acetone, methyl ethyl ketone and methyl. Ketones having 3 or more and 6 or less carbon atoms such as isobutyl ketone; ethers such as tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; aprotonic polar solvents such as dimethyl sulfoxide can be mentioned.
Among these, the solvent is preferably a mixed solvent of water and a non-aqueous solvent, more preferably a mixed solvent of water and a lower alcohol, and further preferably water and a secondary or tertiary solvent having 3 or more and 4 or less carbon atoms. A mixed solvent with alcohol, more preferably water and a mixed solvent of isopropanol or tert-butanol, still more preferably a mixed solvent of water and isopropanol.

When a mixed solvent of water and a lower alcohol is used as the solvent, the mass ratio of the lower alcohol to water (lower alcohol / water) suppresses the aggregation of hydroxyalkyl cellulose and obtains an improved alkyl selectivity. It is preferably 3 or more, more preferably 3.5 or more, still more preferably 4 or more, still more preferably 4.5 or more, and preferably 10 or less, more preferably 8.5 or less, still more preferably 7 or less. More preferably, it is 6.5 or less.

In step 1, the content of hydroxyalkyl cellulose (hydroxyalkyl cellulose / (hydroxyalkyl cellulose + solvent) × 100) with respect to the total mass of the solvent and hydroxyalkyl cellulose improves the viewpoint of reducing the amount of solvent used and the reaction efficiency. From the viewpoint of making it, it is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, still more preferably 15% by mass or more, still more preferably 20% by mass or more, and at the time of production. From the viewpoint of facilitating stirring, it is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, still more preferably 30% by mass or less.

In step 1, it is preferable that the hydroxyalkyl cellulose and the solvent are stirred, then a basic compound is added, and after further stirring, an alkyl glycidyl ether is added and reacted.
The reaction temperature in step 1 is preferably 55 ° C. or higher, more preferably 60 ° C. or higher, still more preferably 65 ° C. or higher, still more preferably 70 ° C. or higher, still more preferably 75 ° C. or higher, from the viewpoint of improving the reaction rate. From the viewpoint of suppressing side reactions, the temperature is preferably 100 ° C. or lower, more preferably 95 ° C. or lower, still more preferably 90 ° C. or lower, still more preferably 85 ° C. or lower.

<Process 2>
In the present invention, it is preferable to have a step of further reacting with the cationizing agent (hereinafter, also referred to as “step 2”) after the step 1. When the method for producing a cellulose derivative of the present invention has steps 1 and 2, the obtained cellulose derivative has a structure in which an alkyl group and a cationic group are introduced into hydroxyalkyl cellulose.
The compounds and reaction conditions used in step 2 will be described below.

(Cationizing agent)
A cationic group is introduced into the alkylated hydroxyalkyl cellulose obtained in step 1 by the cationizing agent used in the method for producing a cellulose derivative of the present invention.
Here, the cationic group preferably means a quaternary ammonium salt or a tertiary amine which can be converted into a quaternary ammonium salt by adding a proton and a salt thereof (tertiary amine salt).
As the cationizing agent, a compound represented by the following formula (2) is preferable.

(In the formula (2), R ^{21 to} R ²³ independently represent a hydrocarbon group having 1 or more and 24 or less carbon atoms, X ⁻ indicates an anion, and t indicates an integer of 0 or more and 3 or less.)

In the formula (2), R ^{21 to} R ²³ each independently represent a hydrocarbon group having 1 or more carbon atoms and 24 or less carbon atoms from the viewpoint of solubility, preferably a hydrocarbon group having 1 or more carbon atoms and 12 or less carbon atoms. Yes, more preferably a linear or branched hydrocarbon group having 1 or more and 4 or less carbon atoms. Specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group and isobutyl group. Among these, a methyl group or an ethyl group is preferable, all of R ^{21 to} R ²³ are more preferably a methyl group or an ethyl group, and all of R ^{21 to} R ²³ are further preferably a methyl group.
In the formula (2), t represents an integer of 0 or more and 3 or less, preferably an integer of 1 or more and 3 or less, more preferably 1 or 2, and even more preferably 1.
X ⁻ represents an anion and is a counterion of a quaternary ammonium cation. Specifically, alkyl sulfate ions having 1 or more and 3 or less carbon atoms, sulfate ions, phosphate ions, carboxylic acid ions (formic acid ions, acetate ions, propionic acid ions) having 1 to 3 carbon atoms, and halide ions Illustrated.
Among these, from the viewpoint of ease of production and availability of raw materials, X ⁻ is preferably one or more selected from alkyl sulfate ions, sulfate ions, and halide ions having 1 or more and 3 or less carbon atoms. It is preferably a halide ion. Examples of the halide ion include fluoride ion, chloride ion, bromide ion, and iodide ion, but from the viewpoint of water solubility and chemical stability of the obtained polysaccharide derivative, chloride ion and bromide ion are preferable. One or more selected from, more preferably chloride ions.
X ^- may be one kind alone or two or more kinds.

Specific examples of the cationizing agent represented by the formula (2) include chlorides, bromides and iodides of glycidyltrimethylammonium, glycidyltriethylammonium and glycidyltripropylammonium, respectively.
Among these, chlorides or bromides of glycidyltrimethylammonium or glycidyltriethylammonium are preferable, and glycidyltrimethylammonium chloride is more preferable, from the viewpoint of availability of raw materials and chemical stability.
These cationizing agents can be used alone or in combination of two or more.

The amount of cationizing agent to be used may be suitably selected in consideration of the reaction yield and the degree of substitution desired cationic group (MS _C) but obtained, water-soluble cellulose derivatives, and the effect of the present invention From the viewpoint, the amount is preferably 0.01 mol or more, more preferably 0.03 mol or more, still more preferably 0.05 mol or more, still more preferably 0. Mo. It is 1 mol or more, and is preferably 30 mol or less, more preferably 10 mol or less, still more preferably 1 mol or less, still more preferably 0.5 mol or less, from the above viewpoint and the viewpoint of the production cost of the polysaccharide derivative.
The method of adding the cationizing agent may be batch, intermittent, or continuous.

In the present invention, a cleaning step may be provided between the steps 1 and 2, but it is preferable not to have the cleaning step from the viewpoint of production efficiency. After the step 1, it is preferable to carry out a cationization reaction without removing the basic compound by a washing step. In the washing step, the alkylated hydroxyalkyl cellulose obtained in step 1 is washed with a solvent such as hot water, isopropyl alcohol, or acetone to remove unreacted alkylglycidyl ether, neutralize, or the like. This is a step of removing the basic compound as a salt. After the washing step, filtration and drying, the basic compound is re-added to cause a cationization reaction.

The reaction temperature in step 2 is preferably 65 ° C. or lower, more preferably 60 ° C. or lower, still more preferably 55 ° C. or lower from the viewpoint of obtaining reactivity, and preferably 20 ° C. or higher from the viewpoint of reaction rate. It is more preferably 30 ° C. or higher, further preferably 40 ° C. or higher, still more preferably 45 ° C. or higher.

When the cationizing agent is in a liquid state, it may be used as it is, or it may be diluted with a good solvent such as water or a non-aqueous solvent and added. As the non-aqueous solvent used for dilution, the above-mentioned solvent is similarly exemplified.

After completion of the reaction in step 2, the basic compound can be neutralized with an acid. Neutralization is preferably performed after the completion of all reactions. As the acid, an inorganic acid such as sulfuric acid, hydrochloric acid or phosphoric acid, or an organic acid such as acetic acid or lactic acid can be used.
If necessary, the cellulose derivative obtained after the completion of all the reactions during the production of the cellulose derivative is separated by filtration or the like, or washed with hot water, hydrous isopropyl alcohol, hydrous acetone solvent, etc. for unreacted hydroxyalkylation. It can also be used after removing agents, alkylating agents, anionic agents, cationizing agents, by-products derived from these reactants, and salts produced by neutralization. In addition, as a purification method, general purification methods such as reprecipitation purification, centrifugation, and dialysis can be used.

Steps 1 and 2 are preferably carried out in an inert gas atmosphere such as nitrogen, if necessary, from the viewpoint of suppressing coloring and lowering of the molecular weight of the cellulose chain.

In the present invention, the apparatus used in step 1 and step 2 described later includes a flask, a reaction vessel such as a SUS reaction tank, a mixer such as a regigue mixer capable of stirring, a powder, a highly viscous substance, a resin, and the like. Examples thereof include a mixer such as a so-called kneader used for kneading.
Further, when the reaction is carried out on a small scale, a glass container such as a vial may be used.

<Cellulose derivative>
(Degree of substitution)
In the present invention, the degree of substitution of the alkyl group and the cationic group in the obtained cellulose derivative is not particularly limited, and may be appropriately selected depending on the desired properties of the cellulose derivative.
In the present invention, the degree of substitution (MS _R ) of the alkyl group is preferably 0.001 or more, more preferably 0.003 or more, still more preferably 0.005 or more, from the viewpoint of hydrophobic modification by introduction of the alkyl group. , More preferably 0.008 or more, still more preferably 0.01 or more, still more preferably 0.015 or more. The degree of substitution (MS _R ) of the alkyl group in the cellulose derivative is preferably 1 or less, more preferably 0.5 or less, still more preferably 0.3 or less, from the viewpoint of ensuring the solubility of the cellulose derivative in water. , More preferably 0.1 or less, still more preferably 0.08 or less, still more preferably 0.06 or less, still more preferably 0.05 or less, still more preferably 0.04 or less.
The degree of substitution of the alkyl group is measured by the method described in Examples.

In the present invention, the degree of substitution of the cationic groups in the cellulose derivative (hereinafter referred to as "MS _C"), from the viewpoint of imparting adsorptivity due to the charge by introduction of cationic groups is preferably 0.001 or more, more preferably Is 0.005 or more, more preferably 0.01 or more, still more preferably 0.02 or more, still more preferably 0.05 or more, still more preferably 0.07 or more, and suppress excessive charge adsorption. From the viewpoint of obtaining a polysaccharide derivative having solubility in water and high transparency, it is preferably 1 or less, more preferably 0.7 or less, still more preferably 0.4 or less, still more preferably 0.35 or less, still more preferably. It is 0.3 or less, more preferably 0.25 or less, still more preferably 0.2 or less.
The degree of substitution of the cationic group is measured by the method described in Examples.

(Use)
The use of the cellulose derivative obtained by the present invention is not particularly limited, and can be blended in hair cosmetics such as rinses and shampoos, fabric treatment agents, laundry detergents, laundry finishes, laundry cleaning improvers, and fabric softeners. There is no particular limitation, such as blending with an agent.

[Method for improving alkylation selectivity for hydroxyalkyl cellulose]
The method for improving the alkylation selectivity with respect to hydroxyalkyl cellulose of the present invention includes a step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether in the presence of a basic compound to obtain alkylated hydroxyalkyl cellulose. The solvent is a solvent having a solubility of the hydroxyalkyl cellulose at 20 ° C. of 0.7 or less.
According to the above method, the alkyl selectivity can be improved.
The alkyl selectivity is the ratio (%) of the alkyl group (mol) introduced into the hydroxyalkyl cellulose to the added alkyl glycidyl ether (mol).
The alkyl selectivity is preferably 5% or more, more preferably 10% or more, further preferably 15% or more, still more preferably 20% or more, still more preferably 30% or more, still more preferably 35% or more, still more preferably 40. % Or more, more preferably 45% or more, still more preferably 50% or more.
The preferable range of each component and each step used in the above-mentioned improvement method is the same as the above-mentioned method for producing a cellulose derivative.

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

Example 1
[Synthesis of cellulose derivatives]
Hydroxyethyl cellulose (hereinafter referred to as "HEC") (Ashland, Natrosol 250 JR, weight average molecular weight 150,000, degree of substitution of hydroxyethyl group = 2.5) 5.0 g was placed in a 50 mL mighty vial (Maruem) and isopropyl. 23.4 g of alcohol (Fuji Film Wako Pure Chemical Industries, Ltd., Wako First Grade, hereinafter referred to as IPA) and 4.7 g of ion-exchanged water were added. 200 rpm. After stirring for 5 minutes, 0.29 g of sodium hydroxide (Kishida Chemical Co., Ltd., special grade) was added, and the mixture was further stirred for 15 minutes. Next, 0.21 g of lauryl glycidyl ether (Yokkaichi Chemical Co., Ltd., LA-EP) was added, and the mixture was stirred at 80 ° C. for 30 hours to carry out an alkylation reaction.
Further, 0.76 g of glycidyltrimethylammonium chloride (SY-GTA80, Sakamoto Pharmaceutical Co., Ltd.) was added, and the mixture was stirred at 50 ° C. for 1.5 hours to carry out a cationization reaction. Then, 0.53 g of acetic acid (Fujifilm Wako Pure Chemical Industries, Ltd., Wako First Grade) was added, and the mixture was stirred for 30 minutes to carry out a neutralization reaction.
The obtained suspension was transferred to a 50 mL centrifuge tube and centrifuged at 3500 rpm for 1 minute using a tabletop centrifuge (Kokusan, H-28F). The supernatant was removed by decantation, and the same amount of 85% IPA aqueous solution as the removed supernatant was added and redispersed. The operation of centrifugation and redispersion was repeated again, and after the third centrifugation, the precipitate was taken out. The obtained precipitate was dried under reduced pressure at 80 ° C. overnight using a vacuum dryer (Advantech, VR-420) and crushed by an extreme mill (Warling, MX-1200XTM) to obtain powdered cellulose. A derivative was obtained.

[Measurement of weight average molecular weight]
The weight average molecular weight of hydroxyethyl cellulose (HEC) was calculated by GPC (gel permeation chromatography) in terms of polyethylene glycol.
The measurement conditions are as follows.
-Column: TSKgel α-M x 2
Eluent: 50 mmol / L LiBr, 1% CH ₃ COOH, ethanol / water = 3/7
・ Temperature: 40 ℃
・ Flow velocity: 0.6 mL / min

[Measurement of molar average degree of substitution (MS) and selectivity]
<Pretreatment>
After 1 g of the powdered cellulose derivative was dissolved in 100 g of water, the aqueous solution was placed in a dialysis membrane (Spectrapore, molecular weight cut off of 1000) and dialyzed for 2 days. The obtained aqueous solution was freeze-dried overnight using a freeze-dryer (Tokyo University of Science, FDU1100) to obtain a purified cellulose derivative.

<Calculation of cationic group mass by Kjeldahl method>
200 mg of the purified cellulose derivative was precisely weighed, 10 mL of sulfuric acid and 1 Kjeldahl tablet (Merck) were added, and heat decomposition was carried out with a Kjeldahl decomposition device (BUCHI, K-432). After completion of the decomposition, 30 mL of ion-exchanged water was added to the sample, and the nitrogen content (mass%) of the sample was determined using an automatic Kjeldahl distillation apparatus (BUCHI, K-370) to calculate the mass of the cationic group.

<Calculation of alkyl group mass by Zeisel method>
200 mg of the purified cellulose derivative and 220 mg of adipic acid are precisely weighed into a 10 mL vial (Mighty Vial No. 3 of Maruem Co., Ltd.), and 3 mL of the internal standard solution (tetradecane / o-xylene = 1/25 (v / v)) and iodide are formed. 3 mL of hydrogenic acid was added and the mixture was sealed. In addition, a sample for a calibration curve was prepared by adding 2, 4 or 9 mg of 1-iododecane instead of the cellulose derivative.
Each sample was heated at 160 ° C. for 2 hours using a block heater (PIERCE, Realti-ThermIII Heating / Stilring module) while stirring with a stirrer tip. After allowing the sample to cool, the upper layer (o-xylene layer) was recovered and analyzed by gas chromatography (hereinafter, also referred to as GC) (Shimadzu Corporation, GC-2010 plus).
-GC analysis conditions-
Column: Agilent HP-1 (length: 30 m, liquid phase film thickness: 0.25 μL, inner diameter: 32 mm)
Split ratio: 20
Column temperature: 100 ° C (2 min) → 10 ° C / min → 300 ° C (15 min)
Injector temperature: 300 ° C
Detector: FID
Detector temperature: 330 ° C
Driving amount: 2 μL
The mass of the alkyl group in the sample was determined from the detected amount of 1-iododecane obtained by GC.

<Calculation of molar average degree of substitution and selectivity of alkyl groups>
By calculating the mass of the HEC skeleton from the masses of the above-mentioned cation group and alkyl group and the total sample mass and converting each into the amount of substance (mol), the molar average degree of substitution (MS (Alkyl)) of the alkyl group and the cation The molar average degree of substitution (MS (Cation)) of the sex group was calculated. Further, the ratio (mol) of the alkyl group introduced into HEC was determined from the added alkylating agent (mol) and used as the selectivity.

[Calculation of solubility]
5.0 g of HEC (Ashland, Natrosol 250 JR, weight average molecular weight 150,000) was placed in a 50 mL mighty vial (Maruem), and 23.4 g of IPA and 4.7 g of ion-exchanged water were added. 200 rpm. After stirring for 5 minutes, 0.29 g of sodium hydroxide (Kishida Chemical Co., Ltd., special grade) was added, and the mixture was further stirred for 15 minutes. The obtained suspension was transferred to a 50 mL centrifuge tube and centrifuged at 3500 rpm for 1 minute using a tabletop centrifuge (Kokusan, H-28F). Approximately 5 g of the supernatant is precisely weighed and placed in a 50 mL screw vial (Maruem), dried under reduced pressure at 100 ° C. for 2 hours using a vacuum dryer (Advantech, VR-420), and the mass after drying is precisely weighed. did. The ratio of solid content in the supernatant was calculated from the following formula and used as the solubility.
Solubility = solid content after drying the supernatant (g) ÷ (amount of extracted supernatant liquid (g) -solid content after drying the supernatant (g)) x 100

[Judgment of presence / absence of aggregation]
5.0 g of HEC (Ashland, Natrosol 250 JR, weight average molecular weight 150,000) was placed in a 50 mL mighty vial (Maruem), and 23.4 g of IPA and 4.7 g of deionized water were added. 200 rpm. After stirring for 5 minutes, 0.29 g of sodium hydroxide (Kishida Chemical Co., Ltd., special grade) was added, and the mixture was further stirred for 15 minutes. Subsequently, the mixture was stirred at 80 ° C. for 5 hours and then allowed to cool at room temperature for 1 hour.
Regarding the presence or absence of agglomeration, the vial was turned upside down, and the one in which the solid content fell to the bottom within 30 seconds was judged to be non-aggregate, and the one in which the solid content did not fall was taken as a second collection.
After allowing to cool, the vial was turned upside down, and the solid content fell to the bottom within 30 seconds, so it was judged to be non-aggregated.

[Evaluation of formulation fluidity]
An aqueous solution (5 mL) containing 20% by mass of a surfactant (polyoxyethylene (10) lauryl ether (Emargen 110L, Kao Corporation)) and 3% by mass of the cellulose derivative was placed in a 10 mL screw tube (with scale). It was prepared and stirred with a stirrer for 24 hours (20 ° C.) to dissolve.
The obtained solution was turned upside down together with the screw tube, and the fluidity was visually evaluated.
The time it took for almost all solutions (90% or more) to move from top to bottom was measured.
The time it takes for almost all solutions (90% or more) to move from top to bottom is preferably within 5 seconds, more preferably within 3 seconds.

Example 2
[Synthesis of cellulose derivatives]
5.0 g of hydroxyethyl cellulose (hereinafter referred to as "HEC") (Ashland, Natrosol 250 JR, weight average molecular weight 150,000, degree of substitution of hydroxyethyl group = 2.5) was placed in a 50 mL mighty vial (Maruem), and IPA23. 0.4 g and 4.7 g of ion-exchanged water were added. 200 rpm. After stirring for 5 minutes, 0.29 g of sodium hydroxide (Kishida Chemical Co., Ltd., special grade) was added, and the mixture was further stirred for 15 minutes. Next, 0.21 g of lauryl glycidyl ether (Yokkaichi Chemical Co., Ltd., LA-EP) was added, and the mixture was stirred at 80 ° C. for 30 hours to carry out an alkylation reaction.
Then, 0.53 g of acetic acid (Fujifilm Wako Pure Chemical Industries, Ltd., Wako First Grade) was added, and the mixture was stirred for 30 minutes to carry out a neutralization reaction.
The obtained suspension was transferred to a 50 mL centrifuge tube and centrifuged at 3500 rpm for 1 minute using a tabletop centrifuge (Kokusan, H-28F). The supernatant was removed by decantation, and the same amount of 85% IPA aqueous solution as the removed supernatant was added and redispersed. The operation of centrifugation and redispersion was repeated again, and after the third centrifugation, the precipitate was taken out. The obtained precipitate was dried under reduced pressure at 80 ° C. overnight using a vacuum dryer (Advantech, VR-420) and crushed by an extreme mill (Warling, MX-1200XTM) to obtain powdered cellulose. A derivative was obtained.

Examples 3 to 11 and Comparative Examples 1 to 4
Using the same method as in Example 2, the cellulose derivatives of Examples 3 to 11 and Comparative Examples 1 to 4 shown in Table 1 were synthesized and evaluated. Regarding the determination of the presence or absence of aggregation, the case where the solid content fell to the bottom within 30 seconds was determined to be non-aggregation, and the case where the solid content did not fall for 30 seconds or more and remained attached to the top was determined to be aggregate.
In Example 10, butyl glycidyl ether (Yokkaichi Chemical Company Limited, DY-BP) was used as the alkyl glycidyl ether, and in Example 11, cetyl glycidyl ether (Yokkaichi Chemical Company Limited, CE-EP) was used.
Alkyl glycidyl ether was added in an amount of 0.05 mol per 1 mol of AGU.
Further, as the basic compound, an amount equivalent to 0.40 mol was used with respect to 1 mol of AGU of hydroxyalkyl cellulose.
Further, the hydroxyethyl cellulose used in the examples is as follows.
-HEC, molecular weight 150,000: Ashland, Natrosol 250JR, weight average molecular weight = 150,000, degree of substitution of hydroxyethyl group = 2.5
-HEC, molecular weight 300,000: Ashland, Natrosol 250GR, weight average molecular weight = 300,000, degree of substitution of hydroxyethyl group = 2.5
-HEC, molecular weight 720,000: Ashland, Natrosol 250MR, weight average molecular weight = 720,000, degree of substitution of hydroxyethyl group = 2.5
-HEC, molecular weight 1 million: Ashland, Natrosol 250HR, weight average molecular weight = 1 million, degree of substitution of hydroxyethyl group = 2.5

From the results in Table 1, it was shown that in the method for producing a cellulose derivative of the present invention, the occurrence of aggregation was suppressed and a high alkylation selectivity could be obtained. Further, it was shown that, in particular, when hydroxyalkyl cellulose having a lower weight average molecular weight is used as the hydroxyalkyl cellulose, a cellulose derivative having more excellent formulation fluidity can be obtained. Further, it was found that the effect of the present invention is more remarkable because the hydroxyalkyl cellulose having a low weight average molecular weight has high solubility.
On the other hand, in Comparative Examples 1 to 4 in which the solubility of the solvent used exceeds the range of the present invention, aggregation occurred due to the reaction, and production could not be performed. Therefore, the degree of substitution, alkylation selectivity and formulation fluidity could not be evaluated.

According to the present invention, it has been shown that aggregation due to the reaction is suppressed, and an efficient method for producing a cellulose derivative having an excellent alkylation selectivity is provided.
The method for producing a cellulose derivative of the present invention can be suitably used as an efficient method for producing a cellulose derivative, which is expected to be applied to various uses.

Claims (10)

It has a step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether in the presence of a basic compound in a solvent.
The solvent is a solvent having a solubility of the hydroxyalkyl cellulose at 20 ° C. of 0.7 or less.
Method for producing cellulose derivative. The method for producing a cellulose derivative according to claim 1, wherein the content of the hydroxyalkyl cellulose is 20% by mass or more based on the total mass of the solvent and the hydroxyalkyl cellulose. The method for producing a cellulose derivative according to claim 1 or 2, wherein the solvent is a mixed solvent of water and a lower alcohol. The method for producing a cellulose derivative according to claim 3, wherein the mass ratio of the lower alcohol to water (lower alcohol / water) is 3 or more and 10 or less. The method for producing a cellulose derivative according to any one of claims 1 to 4, wherein the hydroxyalkyl cellulose is hydroxyethyl cellulose. The method for producing a cellulose derivative according to any one of claims 1 to 5, wherein the solvent is a solvent having a solubility of the hydroxyalkyl cellulose at 20 ° C. of 0.1 or more and 0.65 or less. The method for producing a cellulose derivative according to any one of claims 1 to 6, wherein the alkyl glycidyl ether is an alkyl glycidyl ether having an alkyl group having 4 or more and 20 or less carbon atoms. The method for producing a cellulose derivative according to any one of claims 1 to 7, wherein the hydroxyalkyl cellulose has a weight average molecular weight of 10,000 or more and 1.5 million or less. The method for producing a cellulose derivative according to any one of claims 1 to 8, further comprising a step of reacting with a cationizing agent. It has a step of reacting hydroxyalkyl cellulose with alkyl glycidyl ether in the presence of a basic compound in a solvent to obtain an alkylated hydroxyalkyl cellulose.
The solvent is a solvent having a solubility of the hydroxyalkyl cellulose at 20 ° C. of 0.7 or less.
A method for improving the alkylation selectivity for hydroxyalkyl cellulose.