JPS6021130B2 - Method for producing aldonic and saccharide mixtures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a mixture of aldonic acid salts and branic acid salts by oxidizing formose sugar.

The aldonic acid salts and nuciferous salts produced by the method of the present invention each have the general formula: HOCH2xCHOHnanCO
OM and MOOCtCH○daynanCOOM (in the formula, n
is an integer from 1 to 6, M represents an alkali metal).

These aldonic acid salt and bran salt mixtures are extremely useful and are widely used in calcium ion masking agents, detergent builders, washing agents for beer and milk bottles, and cement admixtures. Conventionally, aldonic acid salts and branic acid salts have been obtained by oxidizing a hydrolyzate of recommended sugar, by fermenting bran syrup or starch, and the like. However, all of these manufacturing methods require edible carbohydrates as raw materials, and it is preferable to use edible carbohydrates as industrial raw materials for detergents, cement admixtures, etc. from the standpoint of effective resource utilization. It's not a thing. Furthermore, these edible carbohydrates are quite expensive, and the raw material prices fluctuate with changes in market conditions, so they are not suitable as raw materials for manufacturing industrial products. The present inventor focused on these problems, selected formose sugar as a raw material for producing a mixture of aldonic acid salts and saccharide salts, which has a wide range of uses as an industrial raw material, and conducted various research on its oxidation method. The present inventors have discovered a method for producing a mixture of aldonic acid salts and saccharide salts from formose sugar in good yield, and have completed the present invention.

That is, the gist of the present invention is to use formose sugar, preferably in the presence of a catalyst, to adjust the pH of the reaction solution to 6 to 10.
The reaction temperature is maintained at room temperature to 60°C, and the reaction is carried out until the absorption of oxygen is completed.Then, the solution of the reaction solution is maintained at 6 to 12, and the reaction is carried out at a reaction temperature of 50 to 10,000°C to form an aldonic acid salt. and a method for producing a saccharide mixture.

According to the method of the present invention, a mixture of aldonic acid salts and polinates, which have a wide range of uses as industrial raw materials, can be produced industrially and advantageously at low cost.

Formose is a monosaccharide mixture produced when an aqueous formaldehyde solution is condensed in the presence of a basic catalyst, and is a carbohydrate raw material that can be easily chemically synthesized in a single reaction. However, the formose obtained by this method is a mixture of d'-formose and cannot be eaten as is or used as a raw material for fermentation. However, when used as an industrial raw material, which is the target product of the process of the present invention, it can be used in its original form. Moreover, the formose used in the method of the present invention is used as a raw material for producing it.
Formaldehyde does not need to be in an anhydrous state, and an aqueous formalin solution can be used. Furthermore, the aqueous formalin solution may be a crude product containing methanol or the like, and in some cases, a formalin waste solution can also be used. In the method of the present invention, formose used as a raw material is usually produced by the following method.

Add 5 to 1% by weight of methanol to a formalin aqueous solution (formalin concentration 5 to 3% by weight) to make 50 to 60 qo
Heat and react in the presence of a basic catalyst for 15-40 minutes. The basic catalyst used is preferably calcium hydroxide. After reacting for a predetermined time, dilute sulfuric acid is added to neutralize the reaction solution to make it slightly acidic, and then calcium sulfate is precipitated in a furnace, and the reaction solution is used as it is as a raw material for synthesizing an aldonic acid salt and nucinate mixture.

The obtained formose contains glyceralaldehyde with 3 carbon atoms, threthose with 4 carbon atoms, erythrose, ribulose, arabinose, xylose with 5 carbon atoms, sorbose, fructose, galactose, and glucose with 6 carbon atoms. , mannose, etc., various pentyl compounds having 7 carbon atoms
Contains gases. The present inventor conducted detailed research on the oxidation reaction of formose sugar and obtained the following results.
Conventionally, gluconic acid is synthesized from formose sugar by catalytic air oxidation of glucose, etc., for example, by adjusting the pH of the reaction solution.
7-9. In the method of oxidizing with oxygen-containing gas in the presence of a noble metal catalyst at a reaction temperature of room temperature to around 50q0, the reaction progresses only 30-50%, at which point the reaction stops and no further reaction occurs. It doesn't progress. On the other hand, when the reaction temperature is set high, for example around 80 oo, and the pH of the reaction solution is set to 9011 for oxidation, the reaction proceeds nearly 100%, but the yield of aldonic acid salts and branic acid salts is only a low value of around 50%. is not produced, and a high condensate of sugar is produced as a by-product.

However, when the pH of the reaction solution was maintained at 6 to 10 and the reaction temperature was between room temperature and 60 OO, the oxidation reaction was carried out with an oxygen-containing gas in the presence of a noble metal catalyst, and the reaction progressed by 30 to 50% and did not proceed any further. At that point, that is, when the absorption of oxygen into the reaction system is completed, the axis of the reaction liquid is kept at 6 to 12, and the reaction temperature is raised to 55 to 100 qo to cause the reaction.
It was found that the reaction proceeded to nearly 100%, and the selectivity of aldonic acid salts and saccharide salts was also given values of 90 to 95%. Next, the method of the present invention will be explained in detail.

The method of the present invention advantageously uses a catalyst in terms of reaction rate and yield.

As a catalyst, noble metals such as platinum and palladium are used as carriers,
For example, catalysts supported on carbon powder, ulmina, etc., or catalysts containing copper, nickel, etc. are excellent.
The amount of the catalyst used is preferably in the range of 0.1 to 5% by weight based on the reaction solution (aqueous solution containing 10 to 3% by weight of formose sugar).

In the case of a noble metal catalyst, the amount of precious metal carried on the carrier is 0.
．． A range of 5 to 10% by weight is used. Water is suitable as a solvent for carrying out the reaction, but a mixed solvent of water and other solvents may be used.

The reaction in the method of the present invention consists of two stages of reaction, and in the first stage, the pH of the reaction solution is maintained in the range of 60 to 10, preferably 6.5 to 9.0, and the reaction temperature is of,
The reaction is carried out at a temperature of room temperature to 55qC, preferably room temperature to 50C, in the presence of the above-mentioned catalyst, until absorption of the oxygen-containing gas is completed.

Subsequently, in the second stage reaction, the pH of the reaction solution was adjusted to 6 to 12,
Preferably, the range is 7 to 11, and the reaction temperature is 55 to 1.
00oo, preferably in the range of 60 to 85oo. In order to maintain the pH of the reaction solution within the above range, an alkaline substance is successively added in synchronization with the progress of the reaction. That is,
An alkali necessary to immediately neutralize the carboxylic acid produced by the oxidation reaction to form an aldonic acid salt and an alkali metal salt of a sugar acid is added. The alkaline substances used are alkali metal hydroxides, carbonates or bicarbonates.

Air is usually used as the oxygen-containing gas as the oxidizing agent, but oxygen gas or oxygen diluted with another inert gas such as nitrogen may also be used.

The reaction pressure is preferably in the range of normal pressure to 1 atmospheric pressure. The time required for the reaction is approximately 1 to 3 hours for the first stage reaction and 3 to 1 feeding time for the second stage reaction in the case of a batch type reaction. The solution obtained by removing the catalyst from the reaction solution after the reaction is completed can be used as it is or after being concentrated to a predetermined concentration and used for various purposes.

The method of the present invention will be specifically explained below using Examples.

Example: To a crude formalin aqueous solution with a concentration of 12% containing about 5% by weight of methanol, 32g of calcium hydroxide powder was added, and stirring was continued for 25 minutes while heating to 55~60°C, until the reaction solution turned slightly yellow. The reaction is stopped at the reached point,
Dilute sulfuric acid was added to neutralize the reaction solution to make it slightly acidic (pH=6).

Activated carbon powder carrying 2% by weight of palladium was added to the solution obtained by separating the precipitated calcium sulfate, and the mixture was reacted in a stainless steel reactor equipped with a baffle plate. The reactor is equipped with an air blowing pipe and a turbine blade type rope strainer to maintain good contact between the blown air, the reaction liquid, and the catalyst. Air at reaction temperature 4500 pm/mi
Adjust the pH of the reaction solution to 6.0 to 6.0 under normal pressure while blowing with
The reaction was carried out while adding an aqueous solution of caustic soda to maintain the temperature at 8.0.

It took 90 minutes until the first stage reaction stopped progressing.
Next, in order to carry out the second stage reaction, the reaction temperature was increased to 8.
The reaction was carried out while adding an aqueous solution of caustic soda to maintain the pH of the reaction solution at 8 to 10.
The second stage reaction required 6 hours. A portion of the aqueous solution from which the catalyst had been removed was taken and ion-exchanged to liberate the aldonic acid salts and saccharide salts, and then the water was evaporated to obtain a yellowish brown solid. This solid was dissolved in pyridine and silylated, and then analyzed by gas chromatography. The product contains 3% glycolic acid, 2% glyceric acid,
Erythrolactone 3%, threolactone 5%, arabinolactone 4%, gluconic acid 33%, gluconolactone 1
6%, glucosaccharic acid 7% and other aldonic acids and sugar acids 17%. The conversion rate of formose is 95%, and the selectivity to aldonic acid salts and branic acid salts is approximately 9.
It is 0%.

The obtained aqueous solution of aldonic acid salt and saccharide salt was heated to 500 c
When it was concentrated in c. and tested for its effectiveness as a builder for bottle washing and as a cement admixture with sodium gluconate, almost the same results were obtained.

Comparative Example 1 To 2 crude formalin aqueous solutions containing 12% formaldehyde and 5% methanol, calcium hydroxide powder was added as a catalyst for 30 minutes, heated to 590℃, and after 25 minutes of rope frame, dilute sulfuric acid was added to neutralize. , an aqueous formose sugar solution was obtained.

After the calcium sulfate precipitate was separated in the furnace, the aqueous solution was divided into two equal parts, and each was charged into a cylindrical reactor equipped with a baffle plate.
A total of 6% Pd/carbon powder catalyst was added to each reactor. One of the reactors was heated from the outside to 45°C in a hot water bath, and air was blown into the reactor to cause a reaction.

As the reaction progressed, a 20% NaOH aqueous solution was injected into the reaction solution at intervals to maintain the pH of the reaction solution at 6 to 8. It took 1.5 hours to consume 54 tons of 20% NaOH aqueous solution.

Furthermore, even if air is blown into the air, the consumption of NaOH will stop.
The reaction will not proceed any further. At this point, the reaction solution was collected, water was evaporated to dryness under reduced pressure, and then dissolved in pyridine. After silylation, it was analyzed by gas chromatography. As a result, about 45% of the formose sugar was reacted and converted to saccharide, but 50% of the formose sugar remained unreacted. Next, the remaining half of the aqueous formose sugar solution was divided into two halves, and a similar reaction was carried out at a reaction temperature of 80q0,
A 20% NaOH aqueous solution was then injected to adjust the pH of the reaction solution to 8-1.
I tried to keep it at 0.

6. 130 ta of 20% NaOH aqueous solution was consumed in a period of time, and further consumption of NaOH was stopped.

At this point, the reaction solution was collected, silylated and analyzed in the same manner as above, and it was found that almost all of the formose sugar had disappeared, the yield of the produced saccharide was about 50%, and the remainder was tar-like. It was a substance of

Claims (1)

[Claims] 1 When oxidizing formose sugar with an oxygen-containing gas to produce a mixture of aldonic acid salts and saccharide salts, the pH of the reaction solution is
is maintained in the range of 6 to 10, and the reaction temperature is kept between room temperature and 55℃.
formose sugar, which is characterized by reacting at a reaction temperature of 55 to 100°C while maintaining the pH of the reaction solution in a range of 6 to 12. A method for producing an aldonic acid salt and saccharide mixture from.