JPS6055053B2 - Method for producing granular or granular methyl orthobenzoylbenzoate - Google Patents

Description

Detailed Description of the Invention The present invention relates to a method for producing granular or granular methyl orthobenzoylbenzoate (hereinafter abbreviated as OBBM), and more specifically, a production reaction in which OBBM is synthesized by methylating orthobenzoylbenzoic acid. In the case of a liquid, once water is added, the pH is neutralized to near neutrality, heated to 47 to 70°C, and cooled to below the melting point in a dispersed state with stirring.

In addition, in the case of white crystalline powder of OBBM, suspend it in water.
A method for producing granular or granular OBBM characterized by heating and melting at 1 to 70°C or melting in hot water at 51 to 70°C and cooling to below the melting point in a dispersed state with stirring. It is something.

OBBM is a compound that has the structural formula [1] with the structural formula 0, and its properties have recently been recognized as a curing agent for UV inks.
It is generally used as a white powder crystal at ~54°C.

Because it is in powder form, it tends to solidify during storage during the summer, and has poor solubility and workability in solvents when used.Furthermore, since it is a fine powder, it may scatter and adhere to the worker's body or clothes, making it difficult to handle. As a result, there has been a strong desire to improve the quality of OBBM, especially to prevent caking and scattering.The inventors of the present invention have conducted extensive research to improve these drawbacks, and as a result, the melting point of OBBM has been improved. The present invention was achieved by paying attention to the fact that 0BBM is low, and discovering that it is possible to produce granular or granular 0BBM extremely easily and inexpensively.
This method has been developed to prevent caking by changing the shape of M at high temperatures and to easily produce products with excellent workability, and is of extremely great industrial value.

The present invention will be explained in detail below.

The following two methods have been established industrially for the synthesis of 0BBM.

(1) A method of methylating orthobenzoylbenzoic acid with an acid catalyst (for example, sulfuric acid, hydrogen chloride, etc.) in a methanol solvent.

(2) A method in which orthobenzoylbenzoic acid is directly methylated with dimethyl sulfate in an alkaline solvent.

Regarding the production of granular or granular 0BBM according to the present invention, any of these two synthesis methods can be applied, so there is no particular restriction on the synthesis method.

It is also possible to form powdered 0BBM crystals into grains or granules.゛After adding water to the solution containing 0BBM which has completed the reaction, add an appropriate neutralizing agent to neutralize the pH to around 7, or add water to the 0BBM crystal powder to make a suspension, and then form a granular or granular powder. Perform the operation to change the state. That is, in the case of a reaction product liquid of 0 BBM, the temperature is heated to 47 to 70'C to melt it,
In the case of crystalline powder, melt the aqueous suspension by heating to 51-70'C or add hot water of 51-70'C to 0B.
Completely melt the BM.

The melting point of 0BBM is 51~? ℃, but if methanol is mixed in, it will melt even at 4rc.

If the temperature exceeds 70℃, it is economically disadvantageous and 0BB
M may decompose and the product may become colored.

When this molten liquid of 0BBM is vigorously stirred and the temperature is lowered to below the melting point, the 0BBM becomes granular or granular.

The amount of water added in the trick can be small or large, but
When the amount of water is large, the granules become small, and when the amount of water is small, the granules become large, so the particle size can be adjusted as desired. The suitable particle size for commercial products is about 0.5 to 10wt, and to achieve such a particle size, the amount of water added should be 2 to 3 times the amount of the melt (
W/V) is suitable. In addition, when the stirring force is used to form particles or granules, if the stirring speed is high, fine granules will be produced, and if the stirring speed is slow, large granules will be produced.

Granular or granular 0BBM is easily separated by separation operations such as centrifugation and filtration, and becomes a product by drying at about 40C.

In this way, the present inventors have created an industrially easy-to-use 0BBM product by studying and utilizing the characteristics of 0BBM in detail, which is an epoch-making invention.

Next, the present invention will be specifically explained with reference to Examples.

However, these are merely examples and do not limit the present invention in any way.

Example 1 10k9 methanol, 1.1k9 concentrated sulfuric acid, and 2.5k9 orthobenzoylbenzoic acid are added and heated under reflux for 2 hours.

The reaction solution was poured into 7k9 water, neutralized with aqueous ammonia, and then
Melt by heating to C and cool to 2nd generation while stirring. The resulting granular methyl orthobenzoylbenzoate is centrifuged and then dried under reduced pressure at 40C. Yield 2.6k9 Melting point 52~
Seki℃ Example 2 Dissolve 1k9 of hydrogen chloride gas in 10k9 of methanol, add 1.1k9 of orthobenzoylbenzoic acid, and heat to room temperature.
Leave it for m minutes.

After the reaction was completed, methanol was distilled off under reduced pressure, and 10k9 of water was added.
Add.

After adjusting the pH to 7 with aqueous ammonia, the temperature was raised to 60°C to melt methyl orthobenzoylbenzoate, and the mixture was cooled to 15°C with stirring. The resulting particulate methyl orthobenzoylbenzoate is separated and dried with air at 40°C. Yield 1.2k9 Melting point 51-53lC Example 3 Orthobenzoylbenzoic acid 1.1k9 was dissolved in 10% sodium hydroxide solution 4.5e and dimethyl sulfate 1.5k9
After stirring at room temperature for 3 hours and neutralizing to pH 6.8, the resulting crystals were separated.

The crystals are added to 3 kg of hot water at 55°C, melted, and then cooled to 25°C with stirring to obtain granular methyl orthobenzoylbenzoate. After separation, vacuum drying is performed at 40C.
Yield 1.1k9 Melting point 51~S°C Example 4 Methyl orthobenzoylbenzoate 2.0k9 to water 5k9
After suspending the mixture in 100% and heating to completely melt it, and cooling to 35° C. with stirring, granular methyl orthobenzoylbenzoate is obtained.

After separation, dry in a vacuum rotary dryer at 40C. Yield 2.
0k9 Melting point 51~57C

Claims (1)

[Scope of Claims] 1 Add water to the reaction solution for producing methyl orthobenzoylbenzoate to neutralize it to around pH 7, heat and melt at 47 to 70°C,
A method for producing granular or granular methyl orthobenzoylbenzoate, which comprises cooling the dispersed state to below the melting point while stirring. 2. The method for producing granular or granular methyl orthobenzoylbenzoate according to claim 1, wherein the amount of water added is 2 to 3 times the amount (w/v) of the melt. 3 Melt a suspension of crystalline powder of methyl orthobenzoylbenzoate with water by heating to 51 to 70°C, or add hot water at 51 to 70°C to melt and disperse under stirring. A method for producing granular or granular methyl orthobenzoylbenzoate, which comprises cooling to a temperature below its melting point. 4. The method for producing granular or granular methyl orthobenzoylbenzoate according to claim 3, wherein the amount of water added is 2 to 3 times the amount (w/v) of the melt.