JPS58108201A - Preparation of hydroxyalkyl ether of galactomannan - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a hydroxyalkyl ether of galactomannan.

Galactomannan is a neutral polysaccharide composed of a main chain consisting of mannose as a constituent unit and galactomannan as a side chain.In nature, it is mainly contained in large amounts in the seeds of leguminous plants, especially guar beans. Typical vegetable gums whose main ingredient is galactomannan are guar gum made from tossed raw materials and locust bean gum made from raw stovino.

In particular, the neutral polysaccharides used in the present invention include guar gum,
Galactomannan is a general term for substances whose main component is galactomannan, including locust pea gum. Widely used in field and industrial fields. However, when these galactomannans are made into an aqueous solution, they tend to cause agglomeration of powder particles called "mamako", and aqueous solutions of galactomannans are susceptible to attack by bacteria and deteriorate over time, resulting in a decrease in viscosity. It has the disadvantage of causing t.

゛The present inventors arrived at the present invention as a result of studies aimed at developing an improved modified galactomannan that can overcome these drawbacks while maintaining the extremely high viscosity that is characteristic of galactomannan aqueous solutions. .

The hydroxyalkyl ether of galactomannan obtained by the present invention reduces the change in the viscosity of an aqueous solution over time caused by bacteria without impairing the nonionic properties inherent in galactomannan, and the viscosity of the aqueous solution is stable at a pH of 12 or less. It also has the property of being able to maintain high aqueous solution viscosity even in the presence of high concentrations of various salts containing multivalent ions.

Due to these properties, the hydroxyalkylniteryl galactomannan obtained by the present invention can be usefully used mainly in industrial fields such as paper manufacturing, cosmetics, paints, civil engineering and construction, petroleum, and explosives.

A conventionally known method for producing hydroxyalkyl ethers of galactomannan is disclosed in U.S. Patent No. 2496.
There is a method disclosed in No. 670.

In this method, galactomannan is reacted with glycerin monohalohydrin in an alkaline environment using water as a medium, and the transported lactomannan is alkalized and then reacted with glycerin monohalohydrin.

According to such a method, first, the reaction proceeds by desalting reaction, which inevitably leaves a large amount of salt in the product. This fact presents a serious drawback from the user's point of view, which is the presence of excessive ash content in the product. Second
Since the reaction uses water as a medium, galactomannan and the reaction product must be dissolved in water and the reaction must proceed in a state of extremely high viscosity, resulting in nonuniformity of the reaction and nonuniformity of neutralization during the production process. This method cannot be said to be a preferable method because it causes difficulties in process control such as uniformity, stirring, transportation, drying, etc.

Furthermore, thirdly, when using reaction vessels of the same volume, the method using only water as the reaction medium was compared with the method of the present invention in which galactomannan is suspended in a mixture of a hydrophilic organic solvent and water. Regarding the amount of galactomannan that can be charged in the second and second reactions, the present invention has the advantage that a larger amount can be treated.

Further, the method disclosed in US Pat. No. 3,326,890 employs a suspension method similar to the present invention, but the alkaline reagent used in the method disclosed in the patent is
It is an organic ammonium hydroquine.

According to the results of follow-up testing of the method disclosed in the patent by the present inventors, the reaction rate of alkylene oxykite and galactomannan is slow in the method disclosed in the patent, and the reaction time is usually about 3 to 8 hours. The effective utilization rate of the reaction of alkylene oxide to galactomannan is low at less than 40%, which poses economical problems, and the MS (number of moles of alkylene oxide added per anhydrosaccharide unit), which is a measure of the degree of modification of the product, is 0. .1 or less, which is insufficient and the product is unsatisfactory. Furthermore, this method also has disadvantages such as a large amount of unreacted etherification reagent remaining after the reaction.

In view of these circumstances, the present inventors have conducted intensive research to provide a hydroxyalkyl ether of galactomannan that is inexpensive and has excellent performance, and as a result has arrived at the present invention.

The gist of the present invention is that an alkylene oxide is reacted with an alkaline galactomannan suspension obtained by adding an aqueous solution of an alkali metal hydroxide to a mixture of galactomannan, a hydrophilic organic solvent, and water. An object of the present invention is to provide a method for producing a hydroxyalkyl ether of galactomannan.

The object of the present invention is to achieve excellent quality of hydroxyalkyl ether of galactomannan and to provide the product at low cost.

In the present invention, a reaction is carried out by suspending and dispersing galactomannan in a mixture of water and a hydrophilic organic solvent, adding an alkali metal hydroxide, and then adding an alkylene oxide. A major feature is that the process proceeds with galactomannan suspended and dispersed in the medium.

This effect is due to the fact that galactomannan maintains a suspended and dispersed state that unifies the steps of neutralization, washing, purification, etc. after the completion of the hydroxyalkyl etherification reaction, thereby eliminating the complexity of the process, facilitating unit operations, and This has the effect of making operation and maintenance easier.

Furthermore, by using an alkaline earth hydroxide, the amount of basic substance added can be reduced compared to the conventional method, and as a result, the amount of salts produced can be reduced. This has the effect of significantly reducing the amount of salts present in the product and achieving superior quality.

In carrying out the present invention, the amount of galacto-znannane dispersed and suspended in a mixed solvent of water and a hydrophilic organic solvent is greater than when produced using water as a medium in a reactor with the same internal volume. Very many. Furthermore, since the amount of alkali metal hydroxide that is available at low cost is added in a small amount, the hydroxyalkyl ether of galactomannan can be provided at low cost.

What follows is the content of the present invention? This will be explained in more detail.

The form of galactomannan may be in the form of so-called splints obtained by coarsely crushing beans, or in the form of finely crushed powder. Furthermore, powdered galactomannan purified with ether, alcohol, benzene, etc. may also be used. Furthermore, galactomannan whose molecular weight has been lowered through a process can also be used.

A hydrophilic organic solvent refers to an organic solvent that mixes with water without separating from the water when it contains at least 30% by weight. Specific examples include ketones such as acetone, methyl ethyl ketone, and mixtures thereof, but preferably 2-propanol, tertiary
Examples include butanol, acetone, and methyl ethyl ketone.

In addition, the ratio of hydrophilic organic solvent to water after adding the alkali metal hydroxide aqueous solution is 30 nia 0 to 95 nia in weight ratio.
:5 range is preferable.

One of the important requirements of the present invention is that water is an essential requirement for the reaction. When the amount of water decreases below the composition ratio of hydrophilic organic solvent and water of 95:5, the reaction rate of hydroxyalkylation of galactomannan decreases markedly, and the reaction hardly progresses. This is not preferable since the amount of alkylene oxide remaining in the reaction solution becomes extremely large.

As the ratio of water to the mixture of hydrophilic organic solvent and water increases, the reaction rate increases and favorable reaction conditions can be obtained, and the amount of alkylene oxide remaining in the reaction solution after the reaction also decreases. Preferably, the effective utilization rate of alkylene oxide is also increased, and a high rate of 80% can be achieved.

However, the composition ratio of hydrophilic organic solvent and water is 30=7
When the amount of water increases above 0, the hydroxyalkyl ether of galactomannan produced during the reaction no longer remains suspended in the suspending medium, but dissolves, causing the entire reaction system to thicken. . If such a situation occurs, it will no longer be possible to maintain the slurry state and continue the reaction, making it difficult to efficiently perform post-processing steps such as separation and purification of reaction products, and as a result, post-processing steps will become difficult. This results in a situation where the operability becomes extremely poor.

The present invention uses an alkali metal hydroxide as the alkaline reagent. The inventors of the present invention have conducted various studies and found that when an alkali metal hydroxide is used in the production of a hydroxyalkyl ether of galactomannan, the amount of alkali metal hydroxide used is 10% by weight or less based on the galactomannan. It was found that the reaction proceeded well. This fact is a feature not seen when other basic catalysts are used.

As the alkali metal hydroxide, sodium hydroxide and potassium hydroxide are suitable.

The amount of these alkali metal hydroxides added is preferably 10% by weight or less, particularly 5% by weight or less, based on the galactomannan. If the weight ratio exceeds 10, the uniform suspension and dispersion of the galactomannan in the mixture of the hydrophilic organic solvent and water will be inhibited and the galactomannan will become aggregated, which is not preferable. Moreover, the ash content in the obtained product also increases, making it difficult to obtain a hydroxyalkyl etherified product of galactomannan of excellent quality.

The alkylene oxide according to the present invention is a lower alkylene oxide, and examples thereof include ethylene oxide, proprene oxide, 1,2-butylene oxide, butadiene monooxide, and glycide. In the reaction, alkylene oxide can be used in either gas or liquid form, and the entire amount can be charged before the reaction or it can be added to the reaction system sequentially.

The amount of alkylene oxide can be arbitrarily changed depending on the degree of modification of galactomannan, but is preferably between 0.01 and 6 mol, more preferably between 0.01 and 2 mol, per anhydrosaccharide unit of galactomannan. It is.

The reaction is usually carried out at a temperature of 30° C. to 100° C. The reaction time is sufficient to achieve a predetermined degree of modification (MS), and is preferably 2 hours to 24 hours. The form of the reaction vessel may be any one such as a normal pressure reflux type vessel, a pressure stirring vessel, a pressure kneader 1 and a pressure blender. Usually, after the completion of the reaction, the reaction product is neutralized, filtered, washed with an aqueous solution of a water-soluble organic solvent, and then dried and ground to obtain a product.

In the production method of the present invention, the reaction proceeds with galactomannan and its reactants suspended in water and a water-soluble organic solvent, so operations after the reaction can be carried out in a suspended state. The preferred method is to However, the operations after the completion of the reaction do not impose any limitations on the present invention.

A more detailed explanation will be given below in Examples.

Example 1 A 4-ton flask with an internal volume of 1 ton equipped with a starch, condenser, dropping funnel, and thermometer was equipped with two 150-property tools and 20 Wd! 100% of water and guar gum powder with a moisture content of 12%
Add f and stir to make a uniform suspension and dispersion. After that, gradually add 3f of sodium hydroxide to 50m7 from the dropping funnel.
A solution of sodium hydroxide dissolved in water is added dropwise at room temperature. After stirring at room temperature for 1 hour, 15 f of propylene oxide was added dropwise from the dropping funnel, and the entire flask was heated to 80°C in a hot water bath, and the reaction was continued for 7 hours.

Thereafter, the inside of the flask was cooled to 35 DEG C. or lower, and while stirring, 43-g glacial acetic acid was gradually added dropwise through a dropping funnel to neutralize the flask. The reaction system was maintained in a good suspended state throughout the entire reaction process. Thereafter, the reaction product was filtered and an additional 200-
After washing with a 80% 2-propanol water bath solution, the reaction product was filtered again and further washed with 150% 2-propanol, and the reaction product was taken out and dried in a vacuum dryer at 70°C overnight.

Thereafter, the mixture was ground using a coffee mill so that the entire amount passed through 150 meshes to obtain guar gum hydroxypropyl ether. The resulting product had a moisture content of 17% and a yield of 117f. The color of the product was white with a very slight yellow tinge.

The ash content of the product was 12 Ti.

Example 2 In the same reaction vessel as in Example 1, 110 d of acetone and 90 d of acetone were added.
ff+7! of water and 100V of guar gum with a moisture content of 12% were charged and stirred to obtain a suspension dispersion. A potassium hydroxide solution in which 2 g of potassium hydroxide was dissolved in 20 mm of water was gradually added dropwise from the dropping funnel, and stirring was continued for 30 minutes at room temperature.

After that, add 292 of propylene oxide and add 55
The reaction was carried out at ℃ for 6 hours. After the reaction was completed, the contents were cooled to 35° C., and a stoichiometric amount of acetic acid was added dropwise through a dropping funnel for neutralization.

Thereafter, the same operation as in Example 1 was performed to obtain a product.

The product had a yield of 1359 at 20% moisture.

The ash content of the product was 1.0%.

The threads remained in a uniform suspension state during the reaction process.

Example 3 In a pressurized autoclave with an internal volume of 1 ton, guar gum powders with a moisture content of 12%, 1502 and 250%, and 30%
of water and stir to make a suspension dispersion. Thereafter, an aqueous solution of 5f potassium hydroxide dissolved in 80m water is gradually added to the suspension dispersion.

After that, the inside of the autoclave was replaced with nitrogen and stirred for 1 hour, and then 2.5 f of ethylene oxide was added and heated to 55°C for 6 hours.
Allow time to react. After the reaction is completed, the inside of the autoclave is cooled to room temperature, and then replaced with nitrogen again, and the product is taken out.

The reaction product was then neutralized with a stoichiometric amount of glacial acetic acid, filtered and washed with an 80% 2-propanol solution of 250-, filtered again and washed with 150-propanol. Filtered and air dried. The hydroxyethyl ether of guar gum was obtained by grinding with the coffee mill. The resulting product had a moisture content of 20% and a yield of 1802. The ash content of the product was 1.5%, and the product was white with a slight yellowish tinge.

Example 4 1002 locust bean gum powder with a water content of 10% was placed in the same reaction vessel as in Example 1 together with 150 g of 2-glopanol and 30 g of water and stirred to form a uniform suspension dispersion. Thereafter, a sulfurium hydroxide aqueous solution in which sodium hydroxide 21 was dissolved in 50 ml of water was gradually added using a dropping funnel. After stirring at room temperature for 1 hour, propylene oxide at 30F was added dropwise through a dropping funnel, and the entire flask was heated to 55C using a water bath, and the reaction was continued for 10 hours. Thereafter, the inside of the flask was cooled to 35 DEG C. or below, and 4.3-glacial acetic acid was gradually added dropwise through a dropping funnel to neutralize the flask while stirring. After that, the reaction product was filtered and further 200 m7!0
After washing with 88% 2-propertool aqueous solution, filter again.
After further washing with 150-2-propanol, the reaction product was taken out and dried in a vacuum dryer at 70°C all day and night. The obtained product was ground with a coffee mill, and 15
Hydroxypropyl ether of locust bean gum was obtained by passing the entire amount through the mesh.

The resulting product had a moisture content of 21 g and a yield of 145 f. The color of the product was white with a slight yellow tinge, and the ash content of the product was 11%.

Example 5 Into the same reactor as in Example 1, guar gum powder with a moisture content of 12%, 600-2 propatool and 100-prop water were added, and a suspension dispersion was prepared under stirring. Next, a sodium hydroxide solution prepared by dissolving 1.52 ml of sodium hydroxide in 1001 nl of water was gradually added dropwise through the dropping funnel at room temperature. After stirring at room temperature for 1 hour, 299 propylene oxide was added dropwise from the dropping funnel, and the entire flask was heated to 70°C in a water bath, and the reaction was continued for 5 hours.

Thereafter, the inside of the flask was cooled to 35° C. or below, and a stoichiometric amount of acetic acid was gradually added dropwise through a dropping funnel to neutralize the flask while stirring.

The obtained reaction product was filtered and further 70% of 200rnt
After washing with 2Glopanol solution, filter again and add 150
After washing m1 with 2gropanolte, the reaction product was taken out and air-dried all day and night. Then, hydroxypropyl ether of guar gum was obtained by grinding with a coffee mill so that the entire amount passed through 150 meshes. The resulting product had a moisture content of 20 inches and a yield of 108 tons. The product was white with a slight yellow tinge, and the ash content of the product was 0.7%.

Example 6 Into the same reactor as in Example 1, 150 ml of 2-gropanol, 20 ml of water, and guar gum powder 1009 with a water content of 12% were charged and stirred to prepare a suspension dispersion. Then add 5 otnl of sodium hydroxide from 32! A sodium hydroxide solution dissolved in water was gradually added dropwise through a dropping funnel and stirred for 1 hour.

Thereafter, the temperature of the reaction system was raised to 70° C. using a hot water bath, and 159 g of propylene oxide was added using a dropping funnel. After that 2
Propylene oxide 15V every hour for a total of 6 times 12
The reaction continued over time. The reaction product was then heated at 35°C.
After confirming that the mixture had been cooled to the following temperature, 4.31 nl of glacial acetic acid was added dropwise through a dropping funnel to effect neutralization. The subsequent stirring was the same as in Example 1. The product thus obtained is a slightly yellowish powder with a moisture content of 17.3%.
The yield was 143 f and the ash content was 1.5%.

Patent applicant Mitsubishi Acetate Co., Ltd. Mitsubishi Rayon Co., Ltd. Agent Patent attorney 1) Satoshi Muratake

Claims (1)

[Claims] A method for producing a hydroxyalkyl ether of galactomannan, which comprises reacting an alkylene oxide in an alkaline galac+mannan suspension obtained by adding an alkali metal hydroxide to a mixture of a hydrophilic organic solvent, water, and galactomannan.