JPS5924150B2 - Method for producing cis-epoxycalcium succinate - Google Patents

Description

[Detailed Description of the Invention] The present invention is based on the weight average particle size (hereinafter simply referred to as "average particle size").
This invention relates to a method for producing calcium cis-epoxysuccinate having a size of 100 microns or less.

The present inventors have previously completed a method for producing L-1-tartaric acid by microbially hydrolyzing cis-epoxysuccinic acid (Japanese Patent Application No. 8149/1989), and also When salt is microbially hydrolyzed to produce calcium L (to) monotartrate, the raw material concentration can be increased and the reaction time can be shortened, and the production yield of L (-1-) monotartrate can also be increased. I discovered that (Special application 1986-13)
737).

Furthermore, when calcium cis-epoxy succinate is used as a raw material, it has been found that the particle size of the calcium cis-epoxy succinate has a large effect on the reaction rate and reaction yield. It has been found that good results can be obtained by using this as a raw material (Japanese Patent Application No. 50-054956).
Conventional methods for producing calcium cis-epoxysuccinate have been described in which acidic calcium maleate is oxidized with up to an equimolar amount of hydrogen peroxide in an aqueous solution and then boiled to produce calcium tartrate as an intermediate product. (Japanese Patent Publication No. 47-18733), and a method for producing cis-epoxycalcium hydrogen succinate by reacting calcium hydrogen maleate with hydrogen peroxide in an aqueous solution in the presence of a water-soluble epoxidation catalyst (Japanese Patent Publication No. 47-18733). Showa 49-4
9916), it is stated that calcium cis-epoxysuccinate is produced when the pH during the reaction is higher than 4.

However, none of these methods isolate calcium cis-epoxy succinate, and calcium cis-epoxy succinate with an average particle size of 100 microns or less cannot be obtained by these methods. One possible way to make crystal particles finer is to grind coarse particles, but industrially grinding large amounts of particles requires complicated equipment and operations, requires a large amount of money, and is not practical. isn't it. Therefore, it is industrially important to produce calcium cis-epoxysuccinate in the form of fine particles. In view of the above circumstances, the present inventors have completed the present invention as a result of extensive research in order to obtain fine particles of high purity cis-epoxycalcium succinate.

That is, the present invention involves reacting an aqueous solution or aqueous suspension containing 0.4 to 0.6 gram atoms of a calcium compound with hydrogen peroxide in the presence of an epoxidation catalyst per mole of maleic acid. , cis-epoxycalcium succinate having an average particle size of 100 microns or less by adding a calcium compound to 1 mol of raw maleic acid at 40°C or less so that the amount of calcium compound including the initial addition is approximately 1 gram atom. This is a method for producing calcium cis-epoxysuccinate, which is characterized by crystallizing cis-epoxycalcium succinate. Cis-epoxycalcium succinate having an average particle size of 100 microns or less is one in which the particle size of 90% or more of its weight is less than twice the average particle size.

As maleic acid, maleic acid or maleic anhydride is used.

As the calcium compound, calcium oxide, calcium hydroxide, calcium carbonate, calcium acetate, calcium nitrate, calcium formate, etc. can be used. The ratio of the calcium compound added to 1 mole of maleic acid needs to be in the range of 0.4 to 0.6 gram atom of calcium.

If calcium is less than 0.4 gram atom, even if the desired cis-epoxy succinic acid is produced in the epoxidation reaction, the production rate is slow and the produced cis-epoxy succinic acid may undergo hydrolysis during the reaction. As a result, the yield of cis-epoxycalcium succinate is reduced, and DL-calcium tartrate is mixed into the product. For this reason, when L(4) monotartaric acid is microbially produced from the obtained calcium cis-epoxysuccinate, a drawback arises in that DL monotartaric acid is mixed into the product. Furthermore, if calcium exceeds 0.6 gram atom, cis-epoxycalcium succinate will crystallize during the epoxidation reaction, but in this case, the crystallized particles will have a large average particle size, and the target Crystals with small particle size cannot be obtained. P after addition of calcium compound
H is preferably less than 4. As the epoxidation catalyst, tungstic acid, molybdic acid, tungsten or molybdenum heteropolyacids, or salts of these acids can be used. Further, catalysts in which these acids or salts are supported on a reaction-inert carrier can also be used. The amount of the catalyst used is preferably 0.001 to 0.05 gram atom, particularly preferably 0.002 to 0.02 gram atom, in terms of tungsten or molybdenum per mole of maleic acid. The optimum amount may be selected depending on the molar ratio of maleic acid and hydrogen peroxide, reaction temperature, etc.

The amount of hydrogen peroxide used per 1 mole of maleic acid is 0.8
~1.1 mol is suitable.

Hydrogen peroxide may generally be used as an aqueous solution. Most of the maleic acid is epoxidized using substantially equimolar hydrogen peroxide to maleic acid, but complete epoxidation can be achieved by using a small amount of hydrogen peroxide in excess. Furthermore, if the molar ratio of hydrogen peroxide is lower than that of maleic acid, a calcium compound is added after the epoxidation reaction to crystallize calcium cis-epoxysuccinate, and unreacted maleic acid remains as a calcium salt in the separated mother liquor. However, since this mother liquor containing calcium maleate and a soluble catalyst can be recycled and reused in the next reaction, there is no problem in practice that calcium maleate remains unreacted. The reaction temperature is 70°C or less, preferably 40 to 60°C.

By increasing the amount of catalyst used, the reaction temperature can be lowered and the formation of undesirable reaction by-products can be suppressed. The higher the reaction temperature, the faster the reaction rate,
Also, the amount of catalyst used can be reduced, but above a certain temperature, the hydrolysis of the produced cis-epoxysuccinic acid becomes significant and DL monotartaric acid is produced, making it difficult to obtain calcium cis-epoxysuccinate with high purity. . After the epoxidation reaction is completed, the temperature of the reaction solution is lowered to 40° C. or lower, and the above-mentioned calcium compound is added to form crystals of calcium cis-epoxysuccinate. After the epoxidation reaction is completed, the reaction solution is adjusted so that the amount of calcium compound is 0.5 g or more per mole of maleic acid used, and then the reaction solution is cooled and the crystals that have crystallized are separated. The calcium compound may be added after resuspending the solution in a suitable solvent such as water at a temperature below 40'C. The temperature at which the calcium compound is added has a large effect on the particle size of the calcium cis-epoxysuccinate produced. That is, when the addition temperature exceeds 40°C, the particle size of the produced calcium cis-epoxy succinate becomes large, and fine particles of calcium cis-epoxy succinate with an average particle size of 100 microns or less can only be obtained at 40°C or lower. Since the average particle size of calcium cis-epoxysuccinate can be reduced as the temperature is lowered to 40° C. or lower, the temperature at which the calcium compound is added may be determined according to the desired particle size.

The amount of calcium compound added here should be such that the sum of the amount of calcium compound added during the epoxidation reaction is approximately 1 gram atom of calcium per mol of maleic acid used. The pH of the reaction solution after adding the compound is around neutral, for example 5 to 9.
It is desirable that it be adjusted to As a result, the solubility of cis-epoxycalcium succinate in water is approximately 1.
% or less, and cis-epoxycalcium succinate is almost completely crystallized. The reaction product obtained in this manner is obtained by separating calcium cis-epoxysuccinate by methods such as filtration and centrifugation, and washing, etc. to remove impurities such as calcium maleate, DL calcium monotartrate, and the catalyst. Fine particles of calcium cis-epoxysuccinate can be obtained.

▲ If the mother liquor contains a soluble catalyst, it can be recycled and reused in the next reaction. When a solid catalyst is used for epoxidation, the catalyst can be separated by sieving or other suitable method after the epoxidation reaction is completed, or after the production of calcium cis-epoxysuccinate, and then the catalyst can be reused. Next, the present invention will be explained by examples. Example 1 Maleic anhydride 98y is dissolved in 400 ml of water, and 5.67 ml of sodium tungstate (dihydrate) and 507 ml of calcium carbonate (0.5 gram atom of calcium per mol of maleic acid) are added and dissolved. .

While maintaining the temperature of the reaction solution at 30° C., 102 y of 35% hydrogen peroxide solution was added dropwise over 1 hour. 3 more after dripping
7 hours at 0℃. After the reaction, calcium carbonate 507 is gradually added at a temperature of 30° C., and stirring is continued until the generation of carbon dioxide gas stops. Afterwards, the crystals formed are filtered, washed with water, and dried to form cis-epoxycalcium succinate (5
Crystals 2487 (purity 99.5%) of hydrate salt) were obtained. The average grain size of the crystals was 72μ. Example 2 49 grams of maleic anhydride was dissolved in 300 ml of water, and 2.47 grams of sodium molybdate (dihydrate) and 20,37 grams of calcium hydroxide (0.55 grams atom as calcium per mol of maleic acid) were added. Add and dissolve.

35% hydrogen peroxide solution 517 was added dropwise at 50°C, and the reaction was further carried out at 50°C for 5 hours.

Afterwards, the reaction solution was cooled to 30°C, and calcium hydroxide 16
．． 77 (0 as calcium per 1 mole of maleic acid)
．． 45 g atoms) was gradually added while maintaining the reaction temperature at 30°C. Stir for 1 hour. 1. When the crystals formed after stirring are collected, cis-epoxycalcium succinate (pentahydrate) 1
127 (purity 98%) was obtained.

The average grain size of the crystals was 83μ. Example 3 Maleic anhydride 987 is dissolved in 500 ml of water and 1.3 f7 of sodium tungstate (dihydrate) and calcium carbonate in the amount shown in the table below are added.

35% hydrogen peroxide solution with reaction temperature of 50'C 97.2
y was added dropwise, and the reaction was further carried out at 50°C. While maintaining the reaction solution at 20°C, add calcium carbonate so that the sum of the amount added during the epoxidation reaction is 1007 (1 gram atom of calcium per mol of maleic acid).
Stir until carbon dioxide gas evolution stops. Example 4 Maleic anhydride 98 The results of collecting a large amount of the generated crystals are shown in the following table.
Dissolve y in 400 ml of water, add 0.667 sodium tungstate (dihydrate) and 37 f calcium hydroxide (
0.5 g atom of calcium per mole of maleic acid) is added and dissolved.

At a reaction temperature of 60°C, 60% hydrogen peroxide solution 51f7 was added dropwise, and the reaction was further carried out at 60°C for 3 hours. After cooling the reaction solution, gradually add calcium carbonate 507 (0.5 gram atom of calcium to 1 mole of maleic acid) at the temperature shown in the table below, stir until the generation of carbon dioxide gas stops, and reduce the temperature of the solution to 2.
Bring to 0°C and stir for an additional hour. The results of collecting a large amount of the generated crystals are shown in the table below. Example 5 98 y of maleic anhydride is dissolved in 300 ml of water and 1.37 y of sodium tungstate (dihydrate) and 60 y of calcium carbonate (0.6 gram atom as calcium per mol of maleic acid) are added.

Add 99 y of 35% hydrogen peroxide solution at 60°C, and then
The reaction is carried out at 0°C for 4 hours.

The reaction solution was cooled, a lot of the crystals formed were collected, and the crystals were
Suspend in 00ml of water. Calcium carbonate 4 at 10℃
0y (0.4 g atom per mole of maleic acid) was gradually added to this slurry, stirred until no carbon dioxide gas was generated, and the formed crystals were collected to give cis-epoxycalcium succinate (pentahydrate) 244y. (purity 99%) was obtained.

The average grain size of the crystals was 75μ.

Claims (1)

[Claims] 1. An aqueous solution or aqueous suspension containing 0.4 to 0.6 gram atoms of a calcium compound per mole of maleic acid is reacted with hydrogen peroxide in the presence of an epoxidation catalyst, and then heated at 40°C. Below, by adding a calcium compound to 1 mol of raw maleic acid so as to make approximately 1 gram atom of calcium, including the initial addition of calcium compound, cis-
A method for producing calcium cis-epoxysuccinate, which comprises crystallizing calcium epoxysuccinate.