JP4337305B2 - Process for producing dry 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane - Google Patents

Description

【００２０】
【発明の効果】
本発明によれば、乾燥機の内壁に形成されるスケーリングが抑制され、乾燥ＳＰＧ粉体が効率的に製造される。
【図面の簡単な説明】
【図１】本発明の実施例１で用いた乾燥機の概略図
【図２】本発明の実施例２で用いた乾燥機の概略図
【符号の説明】
１・・乾燥機、２・・湿潤粉体導入口、３・・乾燥粉体排出口、４・・ジャケット、５・・加熱媒体入口、６・・流動化手段、７・・排気口、８・・コンデンサー、９・・ブロアー、１０・・加熱媒体出口、１１・・循環ガス加熱用熱交換器、Ｍ・・攪拌モーター[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing dry 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane <hereinafter referred to as SPG> Specifically, at least by a drier having an inlet for SPG powder wetted with a solvent, a discharge port for dry SPG powder, fluidizing means for the wet powder, and a jacket on the outer wall of the drier. The present invention relates to a method for producing dry SPG powder.
[0002]
[Prior art]
When producing dry SPG powder, conventionally, at least an inlet for SPG powder wetted with a solvent, an outlet for dry SPG powder, a fluidizing means for the wet powder, and a dryer The wet powder was indirectly heated by a dryer having a jacket on the outer wall through a heating medium having a temperature lower than the melting point of the dry powder and lower than the boiling point of the solvent.
[0003]
[Problems to be solved by the invention]
However, when drying SPG powder moistened with a solvent, if the jacket is indirectly heated through a heating medium below the boiling point of the solvent, SPG scaling is formed on the inner wall surface of the dryer in contact with the jacket, and heat transfer efficiency There was a problem that the remarkably decreased.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventor indirectly passed the wet powder through a heating medium having a temperature lower than the melting point of the SPG and higher than the boiling point of the solvent. It has been found that heating can suppress the formation of scaling and improve the drying efficiency, thus completing the present invention.
[0005]
That is, the present invention provides at least 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane powder moistened with a solvent. And an outlet for the dried 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane powder, Using a drier having fluidizing means for the wet powder and a jacket on the outer wall of the drier, the boiling point of the solvent (° C.) [a plurality of solvents in which the powder charged into the inlet does not have an azeotropic composition. When wetted, the highest boiling point of multiple solvents is the boiling point of the solvent (° C.), and when the powder charged into the inlet is wetted with multiple solvents having an azeotropic composition, the highest boiling point of multiple solvents Value and the azeotropic point in multiple solvents Let the higher temperature be the boiling point of the solvent (° C.)] A dry 3,9-bis, characterized in that the wet powder is indirectly heated by passing a heating medium in the temperature range of about 190 ° C. through the jacket. A method for producing (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane is provided.
Hereinafter, the present invention will be described in detail.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As a preferred dryer used in the present invention, for example, as shown in FIG. 1 and FIG. 2, a heating jacket 4 is provided on the outer wall of the dryer body 1, and the inlet 2 for wet SPG powder is The thing provided in the side part or upper part of a dryer is mentioned. Moreover, it is preferable that the discharge port 3 for the dry SPG powder is provided at the lower part of the dryer.
[0007]
The powder fluidizing means 6 may be a stirring blade that rotates about an axis, the dryer itself may rotate, or the dryer body may vibrate. Examples of the stirring blade include a paddle blade, an anchor blade, and a ribbon blade.
[0008]
The dryer used in the present invention may have a condenser 8 for condensing water evaporated from the wet SPG powder during drying, a solvent such as a hydrophilic organic solvent or a hydrophobic organic solvent, and the above condenser. You may have the exhaust port 7 and the vacuum pump which exhaust the solvent vapor | steam which is not condensed. Further, gas may be vented or circulated into the dryer. The gas is circulated by a blower 9 as described in FIG. Examples of the gas to be ventilated or circulated include air, nitrogen, helium, argon, carbon dioxide and the like, and nitrogen is more preferable.
[0009]
In the present invention, when the powder charged into the inlet is wetted with a plurality of solvents having no azeotropic composition, the highest boiling point of the plurality of solvents is defined as the boiling point of the solvent. For example, in Examples 1 and 2 described later, the SPG powder is wet with n-heptane and water, and these solvents do not have an azeotropic composition, so water having a boiling point higher than that of n-heptane. It is efficiently dried at a boiling point of 100 ° C. (under atmospheric pressure) or more and a temperature range below the melting point of SPG (preferably a temperature range of 100 ° C. or more and 190 ° C. or less).
[0010]
In the present invention, when the powder charged into the inlet is wetted with a plurality of solvents having an azeotropic composition, for example, when the SPG powder is wetted with ethanol and water, these solvents are Since it has an azeotropic composition (azeotropic point is 58 ° C) and ethanol and water have boiling points of 78 ° C and 100 ° C (under atmospheric pressure), respectively, the highest temperature among azeotropic points of 58 ° C, 78 ° C and 100 ° C Is efficiently dried in a temperature range of 100 ° C. or higher and lower than the melting point of SPG (preferably a temperature range of 100 ° C. or higher and 190 ° C. or lower). Further, when the SPG powder charged into the inlet is wetted with, for example, acetone and chloroform, these solvents have an azeotropic composition (azeotropic point is 63 ° C.), and the boiling points of acetone and chloroform are respectively Since it is 57 ° C. and 61 ° C. (under atmospheric pressure), the temperature range is 63 ° C. or higher, which is the highest temperature among the azeotropic points of 63 ° C., 57 ° C. and 61 ° C., and below the melting point of SPG (preferably 100 ° C. In the temperature range below ℃).
The temperature of the heating medium is preferably 15 ° C. or more higher than the boiling point of the solvent, and by making it 15 ° C. or more higher than the boiling point of the solvent, dry SPG having a solvent amount of 0.5% by weight or less can be obtained.
[0011]
【Example】
EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further in detail, this invention is not limited at all by these examples.
[0012]
Example 1
The SPG powder moistened with n-heptane / water was dried under the following conditions using the dryer shown in FIG.
Wet powder introduction rate: 240kg / h
Stirring speed: 190 revolutions per minute Fluidization means: Paddle blade aeration gas rotating around the axis: Nitrogen
Gas flow rate: 75m ^{3 /} h (standard state)
Melting point of SPG: 192-198 ° C
Boiling point of n-heptane: 98.4 ° C
Boiling point of water: 100 ° C
Pressure: Normal pressure (atmospheric pressure)
Heating medium: Heated steam (119-129 ° C)
[0013]
As a result of drying the SPG under the above conditions, scaling was suppressed and a dried SPG having a moisture content of 0.2% by weight or less could be obtained.
[0014]
Example 2
Using the drier shown in FIG. 2, the SPG powder moistened with n-heptane / water was dried under the following conditions.
Wet powder introduction rate: 22kg / h
Stirring speed: 600 revolutions per minute Fluidization means: Paddle blade aeration gas rotating around the axis: Nitrogen gas aeration amount: 0.23 m ^{3 /} hour (standard state)
Melting point of SPG: 192-198 ° C
Boiling point of n-heptane: 98.4 ° C
Boiling point of water: 100 ° C
Pressure: Normal pressure (atmospheric pressure)
Heating medium: Heated steam (141 ° C)
[0015]
As a result of drying the SPG under the above conditions, scaling was suppressed and a dried SPG having a water content of 0.1% by weight or less could be obtained.
[0016]
Comparative Example 1
Using the drier shown in FIG. 2, the SPG powder moistened with n-heptane / water was dried under the following conditions.
Wet powder introduction rate: 172 kg per hour
Stirring rotation speed: 190 rotations per minute Fluidization means: Paddle blade aeration gas rotating around the axis: Nitrogen gas aeration amount: 40 m ^{3 /} hour (standard state)
Melting point of SPG: 192-198 ° C
Boiling point of n-heptane: 98.4 ° C
Boiling point of water: 100 ° C
Pressure: Normal pressure (atmospheric pressure)
Heating medium: Hot water (80 ° C)
[0017]
SPG was dried under the above conditions, but scaling of a thickness of about 5 mm was observed on the inner wall of the dryer, and only SPG powder containing 11 to 13% by weight of water was obtained.
[0018]
The overall heat transfer coefficient of the dryer inner wall at the time of drying in Example 1, Example 2 and Comparative Example 1 was measured. The results are shown in the table below. In Example 1 and Example 2, compared with the comparative example 1, it turns out that the overall heat transfer coefficient is improving about 2 times.
[0019]

[0020]
【The invention's effect】
According to the present invention, scaling formed on the inner wall of the dryer is suppressed, and dry SPG powder is efficiently produced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a dryer used in Example 1 of the present invention. FIG. 2 is a schematic diagram of a dryer used in Example 2 of the present invention.
1 .... Dryer, 2 .... Wet powder inlet, 3 .... Dry powder outlet, 4 .... Jacket, 5 .... Heating medium inlet, 6 .... Fluidization means, 7 .... Exhaust port, 8・ ・ Condenser, 9 ・ ・ Blower, 10 ・ ・ Heating medium outlet, 11 ・ ・ Heat exchanger for circulating gas heating, M ・ ・ Agitator motor

Claims (6)

At least an inlet for 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane powder wet with a solvent and drying 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane powder outlet and flow of the wet powder And a dryer having a jacket on the outer wall of the dryer, the boiling point of the solvent (° C.) [a plurality of powders when the powder charged into the inlet is wetted with a plurality of solvents having no azeotropic composition The highest boiling point of the solvent is the boiling point of the solvent (° C.), and when the powder charged into the inlet is wetted with a plurality of solvents having an azeotropic composition, the highest boiling point of the plurality of solvents and the plurality of solvents Compare the azeotropic point with the higher temperature A medium boiling point (° C.)] through to 1 90 ° C. jacket heating medium temperature range, dry 3,9-bis characterized by indirectly heating the wet powder (1,1 (Dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane production method.   The method according to claim 1, wherein the fluidizing means is a wing or a pin. The method according to any one of claims 1 to 2, wherein the solvent for wetting the powder charged into the charging port is a mixture of n-heptane and water.   The method according to any one of claims 1 to 3, wherein the drying is performed while the airflow is aerated or circulated. The method according to claim 4, wherein the air flow to be ventilated or circulated is an air flow comprising nitrogen.   The method according to any one of claims 1 to 5, wherein the heating medium is at a temperature 15 ° C or higher than the boiling point of the solvent.

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