JPH04257527A - Solidification of organic compound and equipment therefor - Google Patents

Abstract

PURPOSE:To solidify an organic compound easily in a short time from its concentrated solution being in a vitreous state at normal temperatures. CONSTITUTION:A concentrated solution in a vitreous state at normal temperatures containing a specified concentration of an organic compound is kept at -10 to 50 deg.C, and specified amount of seed crystal is added to this solution in a mixer 18 equipped with an agitator 19, thus accomplishing the objective solidification. Said concentrated solution can be obtained by injecting a solution of the organic compound into long tube-type steam heating pipes 4 to produce a mixture of a concentrated solution and solvent vapor, followed by injecting the mixture into a vacuum vessel 6.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method and apparatus for solidifying organic compounds including photographic materials such as photographic couplers and color image forming materials (coloring materials), and particularly to a method for solidifying organic compounds from their solutions. and regarding equipment.

0002

BACKGROUND OF THE INVENTION It is advantageous to take out organic compounds such as photographic materials produced by chemical reactions in a solid state from a reaction solution in order to improve their ease of handling such as transportation and weighing. The most common method is a method using so-called reprecipitation. In this method, the reaction solution is added to a crystallization solvent that is a poor solvent for the organic compound dissolved in the reaction solution and a good solvent for the reaction solvent, and the organic compound is crystallized. After filtering, it is dried.

However, in order to carry out this method on an industrial scale, it is necessary to use a large amount of crystallization solvent, and the equipment is also large-sized, making it uneconomical. Moreover, it takes a long time from crystallization to drying.

[0004] In order to shorten the time required for drying, Japanese Unexamined Patent Publications Nos. 58-79501 and 60-90001 disclose a method using a long steam heating tube. In this method, a stock solution containing volatile components and non-volatile components is supplied into a long steam heating tube to evaporate the volatile components, and the obtained non-volatile components are continuously supplied to a cooling grinder to evaporate the non-volatile components. While cooling, solidifying, and pulverizing the components, volatile components in the non-volatile components are further evaporated.

Furthermore, JP-A-2-191501 discloses a method for obtaining a powdery polymer from a polymer solution by drying using a long steam heating tube. In this method, the viscosity of the polymer solution supplied to the heating tube is adjusted in advance to a specific viscosity.

However, when the solution to be dried is in a glass state at 25° C. or lower, the method using an upper long tube type steam heating tube may not be able to obtain the desired substance in a solidified state from the solution, or may be extremely difficult to obtain. proved to be difficult.

[0007] In addition, Japanese Patent Publication No. 14777/1983 states that
As a method for making candy, the patent discloses a method in which raw materials are concentrated at a temperature of about 130°C under reduced pressure, and then cooled to 80 to 85°C to solidify. However, even with this method, it is not possible to obtain a predetermined substance in a solidified state from a solution in a glassy state as described above.

[0008]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a solidification method and apparatus that can relatively easily and quickly solidify a substance that is solid at room temperature from its glassy solution. It is.

[0009]

[Means and effects for solving the problems] In order to solve the above problems, the present invention provides a mixture containing an organic compound that is solid at room temperature and a solvent for the organic compound in an amount of 1 to 50% by weight. Provided is a method for solidifying an organic compound, which comprises maintaining the organic compound at -10°C to 50°C, adding and mixing seed crystals of the organic compound at a ratio of 1 to 20% by weight, and solidifying the organic compound. do.

In the above method, a solution of an organic compound is supplied to a long steam heating tube, and a mixture of a concentrated solution of the organic compound and a gas generated in the heating tube is ejected into a reduced pressure atmosphere. Seed crystals of the organic compound are added to the concentrated solution.

Further, according to the present invention, there is provided a means for supplying a solution of an organic compound that is solid at room temperature, and a long steam heating tube connected to the supply means for producing a concentrated solution of the organic compound. , a container connected to an end of the heating tube different from the connecting end of the supply means and capable of being brought into a reduced pressure state for receiving the concentrated solution under reduced pressure; connected to the bottom of the container and maintaining the reduced pressure state; An apparatus for solidifying an organic compound is provided, which includes means for taking out the concentrated solution, and means for supplying seed crystals of the organic compound to the taken out concentrated solution and then mixing under normal pressure. The present invention will be explained in more detail below.

[0012] The present inventors have discovered the following chemical formula 1, which is a photographic material.
At room temperature (25
When an attempt was made to dry and solidify a solution of a solid organic compound using a long steam heating tube, the organic compound was
Although concentrated, they are still in the form of highly viscous concentrated solutions (these solutions have a viscosity of 10,000 to 100,000 centipoise (cp) at room temperature, are honey-like and hardly flowable), and are solids. could not be obtained in this condition.

[0013]

[Chemical formula 1]

[0014]

[Case 2]

[0015] Therefore, as a result of intensive research on a method for solidifying such a concentrated organic compound in the form of a concentrated solution, the concentrated solution was kept at a temperature of -10°C to 50°C, and the organic compound was added to the concentrated solution. By adding seed crystals at a ratio of 1 to 20% by weight and mixing, the organic compound can be solidified (for example, precipitated as crystals) in a relatively short time.
The present inventors have discovered that it is possible to do this, and have completed the present invention.

[0016] The present invention has a glass transition point of room temperature (25°C).
An organic compound can be crystallized from a concentrated solution of the organic compound in a relatively short period of time (for example, within 1 hour after adding seed crystals). As the organic compound, the above YCp-
In addition to photographic couplers such as A and YCp-B and photographic materials such as colorants, organic compounds in general can be used.

In the present invention, the concentration of the solvent in the concentrated solution of the organic compound is 1 to 50% by weight based on the organic compound, and if it deviates from this range, the effects of the present invention cannot be obtained. A preferred solvent concentration is 1.5 to 15% by weight, more preferably 2 to 10% by weight.

[0018] Such a viscous organic compound solution in a concentrated form (for example, viscosity 10 to 1000 cp) can be used as is if the solvent concentration in the organic compound solution such as the reaction solution is within the above range. Can be done. However, the solvent concentration in the reaction solution is usually higher than the above range, and it is desirable to concentrate this. It is preferable to use a long steam heating tube for this concentration. That is, the reaction solution is supplied from one end to a long heating tube heated with steam. In the heating tube, the solvent evaporates, forming a mixture of concentrated solution of the remaining organic compound and solvent vapor,
When this is injected into the reduced pressure atmosphere from the other end of the heating tube,
A concentrated solution of organic compounds is obtained.

[0019] Examples of the long steam heating tube include:
A known double heating tube, such as that described in Utility Model Publication No. 52-28862, can be used. The inner tube of the double heating tube through which the organic compound solution passes preferably has a length to inner diameter ratio of 100 to 10,000, particularly preferably 500 to 2,000. The inner diameter of the inner tube is usually 3 to 50 mm, preferably 10 mm.
The length is between 25mm and 25mm. Any shape can be used for the outer tube that covers the inner tube as long as it can pass the steam for heating the outer tube. Typically, the outer tube is a cylinder arranged concentrically with the inner tube. As the steam used for heating, it is preferable to use low pressure steam of 50 to 100° C., since the organic compound to be solidified is in a glass state at room temperature or lower. There are no particular restrictions on the method of generating such low pressure steam. For example, JP-A-60-64108
Low pressure steam can be generated by the method described in the publication.

The other end of the long steam heating tube is connected to a reduced pressure atmosphere, specifically to a container capable of achieving and maintaining reduced pressure (reduced pressure container). The gas containing the solvent vapor and the concentrated organic compound solution generated in the long steam heating tube are ejected into the vacuum container, and a concentrated solution of the organic compound is obtained in the vacuum container. In order to adjust the solvent concentration in this concentrated solution within the above range, the feeding rate of the organic compound solution to the heating tube,
Conditions such as the heating temperature by steam and/or the residence time in the heating tube can be adjusted as appropriate. These conditions can be easily determined through preliminary experiments.

[0021] The concentrated solution of the organic compound containing 1 to 50% by weight of solvent thus prepared can be taken out into a separate second container (also a vacuum container for convenient removal). . After taking out, the inside of the second container is returned to atmospheric pressure, and the concentrated solution is transferred to a mixing container, where it is heated at -10°C to 50°C, preferably 0°C to 30°C, more preferably 10 to 25°C. While maintaining the temperature, seed crystals of the organic compound are added in a proportion of 1 to 20% by weight based on the organic compound and mixed. The amount of seed crystals added is preferably 1.5 to 15% by weight, more preferably 2 to 10% by weight. By maintaining this concentrated solution at a predetermined temperature and adding a predetermined amount of seed crystals, the organic compound in the concentrated solution is solidified in a relatively short time. Incidentally, after the seed crystals are added to the concentrated solution and mixed, the mixture can be left on, for example, a belt maintained at room temperature to wait for solidification of the organic compound. The thus solidified organic compound mass is pulverized using a pulverizer and further dried using a drier to obtain a dry powder of the organic compound. FIG. 1 shows an example of an organic compound (concentration) solidification apparatus used to carry out the present invention.

[0022] This device is equipped with a long steam heating double pipe 4 arranged horizontally. A generator 5 that generates low-pressure steam for heating the heating tube 4 is provided near the heating tube 4, and the steam generated here is circulated into the outer tube of the heating tube 4.

One end of the heating tube 4 is connected via a metering pump 3 to the bottom of a solution storage tank 1 for storing a stock solution such as a reaction solution through a line L1. tank 1
can be the reaction tank in which the organic compound was produced. The stock solution is stirred by a stirring device 2 attached to the tank 1 and driven by a motor M, and is supplied to the heating tube 4 at a predetermined rate by a quantitative supply pump 3.

The other end of the heating tube 4 is connected by a line L2 to the upper part of a vacuum container 6 which achieves a reduced pressure atmosphere for blowing out the mixture of gas and concentrated concentrated solution generated in the heating tube 4. There is. The reduced pressure container 6 is equipped with a stirring device 7 driven by a motor M, and a jacket 8 can be provided around the stirring device 7 to keep the entire container warm from the outside temperature.

A reduced pressure generating device 12 is connected to the top of the reduced pressure container 6 via a line L3, thereby maintaining the inside of the reduced pressure container 6 in a reduced pressure state. On line L3,
A solvent vapor condenser 9 and a solvent receiving tank 10 for accommodating the solvent condensed by the condenser 9 are provided in order from the upstream side of the apparatus. A heat insulation jacket 11 can also be provided around the solvent receiving tank 10. Further, a solvent extraction pump 13 is connected to the bottom of the solvent receiving tank 10.

The bottom of the reduced pressure container 6 is connected to a second reduced pressure container 15 via a valve 14. This reduced pressure container 15 receives the concentrated solution in the reduced pressure container 6, and a cooling or heat insulation jacket 16 can be provided around it. At the top of the reduced pressure container 15, via a line L4,
A second reduced pressure generator 17 is connected, thereby maintaining the inside of the reduced pressure container 15 in a reduced pressure state. After receiving a predetermined amount of the concentrated solution in the reduced pressure container 15, the reduced pressure container 15 is returned to atmospheric pressure, the valve 17 provided at the bottom of the container 15 is opened, and the concentrated solution is transferred to the mixing container 18 via the line L5. Move.

The mixing vessel 18 has a stirrer 19 driven by a motor M, and has an inlet 20 at the top for introducing and adding seed crystals. A heat insulating jacket 21 can be attached around the mixing container 18 to maintain its contents (concentrated organic compound solution) at a predetermined temperature. A predetermined amount of seed crystals is added to the concentrated solution in the mixing container 18 from the inlet 20, and the mixture is stirred by the stirrer 19.

A pair of drums 2 are provided below the mixing container 18.
A horizontal endless belt 22 is installed which is appropriately driven by belts 3 and 23. This belt 22 is kept at room temperature, for example, by a cooling jacket 24 through which cooling water circulates. The mixture of the concentrated solution and the seed crystals stirred in the mixing container 18 is spread from the mixing container 18 onto the belt 22 rotated by the drums 23, 23 to a thickness of, for example, 2 to 4 cm. When the mixture reaches the horizontal tip of the upper belt, the rotation of the drums 23 and the supply of the mixture are stopped, and the mixture is left on the belt 22 to wait for the organic compound to solidify.

The solidified organic compound is transferred to drums 23, 23.
is introduced from the belt 22 into a crusher 25 (for example, a pair of gears), where it is crushed. The obtained organic compound powder is transferred to a dryer 26 having a heating jacket 27, where the organic compound powder is further dried and the resulting solvent vapor is discharged through an outlet 27.

[0030]

[Example] Example 1 In this example, YCp-A
Solidified YCp-A was obtained from the solution.

That is, a solution of 100 kg of YCp-A produced and purified in the tank 1 and 500 liters of methylene chloride is supplied to the heating tube 4 by the metering pump 3, and the methylene chloride is evaporated therein. A concentrated solution in which the ratio of methylene chloride to YCp-A was concentrated to 10% by weight was obtained at about 90°C. This concentrated solution was a highly viscous liquid with a viscosity of 500 to 1,000 cp.

After transferring the concentrated solution from the vacuum container 6 to the second vacuum container 15, the inside of the container 15 is returned to atmospheric pressure, and the valve 1 is closed.
7 was opened and the contents were transferred to mixing vessel 18. In this mixing vessel 18, the temperature of the concentrated solution was 40-60°C. Then, 7% by weight based on YCp-A in the concentrated solution
A corresponding amount of YCp-A seeds were added and mixed for about 5 minutes with a stirrer 19 before being spread on belt 22 to a thickness of about 2-4 cm. The belt was maintained at 25°C by a cooling jacket 24. When left on the belt 22 for 1 hour, YCp-
A was solidified. The solidified YCp-A was pulverized by a pulverizer 25 and further dried in a drying device 26 to obtain a powder product. Example 2 A powder of YCp-B was obtained in the same manner as in Example 1 except that YCp-B was used instead of YCp-A.

[0033]

As described above, according to the present invention, even if the concentrated solution has a low glass transition point of 25°C or lower and tends to have a high viscosity at room temperature, it can be removed from the concentrated solution. It can be solidified relatively easily and in a short time. Incidentally, compared to the conventional method of obtaining powder from a reaction solution by crystallization and drying, the method of the present invention takes 1/2 to 1/2 the time.
It will be shortened to 1/10. Furthermore, in the conventional crystallization method, the reaction product is lost by 5% or more, usually by 10% or more, whereas in the present invention, the reaction product can be recovered from the reaction solution without loss.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an organic compound solidification apparatus according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Solution tank, 2, 7, 19... Stirring device, 4... Long steam heating tube, 5... Reduced pressure steam generator, 6, 15... Reduced pressure container, 12, 17... Reduced pressure generator, 18... Mixing container,
22...Belt, 25...Crusher.

Claims (3)

[Claims] Claim 1: A mixture containing an organic compound that is solid at room temperature and a solvent for the organic compound in an amount of 1 to 50% by weight is kept at -10°C to 50°C, and seed crystals of the organic compound are added to the mixture. A method for solidifying an organic compound, which comprises adding and mixing 1 to 20% by weight of the organic compound to solidify the organic compound. 2. A solution of an organic compound that is solid at room temperature is supplied to a long steam heating tube, and a mixture of a concentrated solution of the organic compound and a gas generated in the heating tube is spouted into a reduced pressure atmosphere. 2. The method for solidifying an organic compound according to claim 1, further comprising adding seed crystals of the organic compound to the concentrated solution. 3. A means for supplying a solution of an organic compound that is solid at room temperature; a long steam heating tube connected to the supply means for producing a concentrated solution of the organic compound; connected to an end different from the connecting end of the supply means,
a container capable of being placed under reduced pressure for receiving the concentrated solution under reduced pressure; means connected to the bottom of the container for removing the concentrated solution while maintaining the reduced pressure; and means for removing the concentrated solution while maintaining the reduced pressure; An apparatus for solidifying organic compounds, comprising means for feeding seed crystals of the compound and then mixing under normal pressure.