JP2003055383A - Method for producing dry 3,9-bis(1,1-dimethyl-2- hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a dry 3,9-bis(1,1-dimethy1-2- hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (hereinafter referred to as SPG) without forming scaling of the SPG on the inner wall surface of a dryer in contact with a jacket and without lowering heat transfer efficiency when the SPG powder wetted with a solvent is dried with the dryer provided with a charging port for the wet SPG, a discharging port for the dry SPG, a fluidizing means for the wet SPG and the jacket on the outer wall of the dryer. SOLUTION: A heating medium at a temperature within the range of the following boiling point of the solvent or above and about <=190 deg.C is passed through the jacket. [The boiling point of the solvent is the maximum value ( deg.C) of the boiling points in a plurality of solvent groups when the plurality of the solvents have no azeotropic composition and a temperature ( deg.C) of whichever higher of the maximum value of the boiling points in the plurality of solvent groups and the azeotropic point in the plurality of solvent groups when the plurality of solvents have the azeotropic composition]. Thereby, the wet SPG is indirectly heated.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to dried 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,
Regarding a method for producing 4,8,10-tetraoxaspiro [5,5] undecane <hereinafter referred to as SPG>, more specifically, at least an inlet for SPG powder moistened with a solvent and discharge of dry SPG powder. The present invention relates to a method for producing dry SPG powder by a dryer having an outlet, a fluidizing means for the wet powder, and a jacket on the outer wall of the dryer.

[0002]

2. Description of the Related Art Conventionally, when producing dry SPG powder, at least an inlet for SPG powder wetted with a solvent, an outlet for dry SPG powder, and a fluidizing means for the wet powder have been used. The wet powder was indirectly heated by passing a heating medium having a melting point of the dry powder lower than the melting point of the solvent and a boiling point lower than the boiling point of the solvent through a dryer having a jacket on the outer wall of the dryer.

[0003]

However, when the SPG powder moistened with the solvent is dried, if the heating medium having a temperature lower than the boiling point of the solvent is indirectly heated in the jacket,
There is a problem that SPG scaling is formed on the inner wall surface of the dryer in contact with the jacket, and the heat transfer efficiency is significantly reduced.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that when the wet SPG powder is dried, the jacket is for heating below the melting point of SPG and above the boiling point of the solvent. The present invention has been completed by finding that indirect heating of the wet powder through the medium can suppress the formation of scaling and improve the drying efficiency.

That is, the present invention is directed to at least solvent moistened 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5]. Undecane powder input port and dried 3,
9-bis (1,1-dimethyl-2-hydroxyethyl)
-2,4,8,10-Tetraoxaspiro [5,5] undecane powder discharge port, fluidizing means for the wet powder, and a dryer having a jacket on the outer wall Boiling point (° C) [When the powder introduced into the inlet is wet with multiple solvents that do not have an azeotropic composition, the highest boiling point of the multiple solvents is taken as the solvent boiling point (° C) When the powder to be treated is wet with a plurality of solvents having an azeotropic composition, the highest temperature of the boiling points of the plurality of solvents is compared with the azeotropic point of the plurality of solvents, and the higher temperature is defined as the boiling point (° C.) of the solvent. Dry, 3,9-bis (1,1-dimethyl-2-hydroxyethyl), characterized in that the wet powder is indirectly heated by passing a heating medium in the temperature range of from about 190 ° C. to about 190 ° C. through the jacket. -2,4,8,10-Tetraoxaspiro [5 5] is to provide a method of manufacturing undecane. Hereinafter, the present invention will be described in detail.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred dryer used in the present invention is, for example, as shown in FIGS.
An example is a dryer main body 1 having a heating jacket 4 on the outer wall thereof, and an inlet 2 for the wet SPG powder is provided at a side portion or an upper portion of the dryer. Also, dry S
The discharge port 3 for the PG powder is preferably provided at the bottom of the dryer.

The powder fluidizing means 6 may be a stirring blade that rotates about an axis, the dryer itself may rotate, or the dryer main body may vibrate. Good. Examples of the stirring blades include paddle blades, anchor blades, ribbon blades, and the like.

The dryer used in the present invention is a condenser 8 for condensing water, a solvent such as a hydrophilic organic solvent or a hydrophobic organic solvent, which is evaporated from the wet SPG powder during drying.
May be provided, and an exhaust port 7 and a vacuum pump for exhausting solvent vapor that is not condensed by the condenser may be provided. Further, gas may be ventilated or circulated into the dryer. The gas is blower 9 as shown in FIG. 1, for example.
Circulated by. As the gas to be ventilated or circulated,
For example, air, nitrogen, helium, argon, carbon dioxide and the like can be mentioned, but nitrogen is more preferable.

In the present invention, when the powder charged into the charging port is wet with a plurality of solvents having no azeotropic composition, the highest boiling point of the plurality of solvents is the boiling point of the solvent. For example, in Examples 1 and 2 described later, the SPG powder is n-
Since the solvent is wet with heptane and water, and these solvents do not have an azeotropic composition, the temperature range of the boiling point of water, which is higher than that of n-heptane, is 100 ° C (under atmospheric pressure) or more and less than the melting point of SPG ( It is preferably dried efficiently in a temperature range of 100 ° C. or higher and 190 ° C. or lower).

Further, in the present invention, when the powder charged into the charging port is wet with plural solvents having an azeotropic composition, for example, when the SPG powder is wet with ethanol and water, The solvent has an azeotropic composition (the azeotropic point is 58
℃), the boiling points of ethanol and water are 78 ℃ and 1 respectively.
Since it is 00 ° C (under atmospheric pressure), azeotropic points are 58 ° C and 78 ° C.
And 100 ° C, which is the highest temperature of 100 ° C or higher, S
Temperature range below the melting point of PG (preferably 100 ° C. or higher,
It is efficiently dried in a temperature range of 190 ° C. or lower). Furthermore, when the powder of SPG charged in the charging port is wet 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), a temperature range of 63 ° C. or higher which is the highest temperature among azeotropic points of 63 ° C., 57 ° C. and 61 ° C. and lower than the melting point of SPG (preferably 100 ° C. or higher, 190 It is efficiently dried in a temperature range of ℃ or less). The temperature of the heating medium is preferably higher than the boiling point of the solvent by 15 ° C. or more, and the temperature of the heating medium is raised by 15 ° C. or more so that the amount of the solvent is 0.
Up to 5% by weight of dry SPG can be obtained.

[0011]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Using the dryer shown in FIG. 1, SPG powder wet with n-heptane / water was dried under the following conditions. Introducing speed of wet powder: 240 kg / hour Stirring speed: 190 rotations / min Fluidization means: Paddle blades rotating around a shaft Vent gas: Nitrogen (circulation) Gas flow rate: 75 m ^{3 /} h (standard state) SPG melting point : 192-198 ° C Boiling point of n-heptane: 98.4 ° C Boiling point of water: 100 ° C Pressure: Normal pressure (atmospheric pressure) Heating medium: Heating steam (119-129 ° C)

As a result of drying the SPG under the above conditions, scaling is suppressed and the dry SP has a water content of 0.2% by weight or less.
I was able to obtain G.

Example 2 SPG powder wet with n-heptane / water was dried under the following conditions using the dryer shown in FIG. Introducing speed of wet powder: 22 kg / hour Stirring speed: 600 rpm Fluidization means: Paddle blade rotating around a shaft Vent gas: Nitrogen gas flow rate: 0.23 m ^{3 /} h (standard state) SPG melting point: 192-198 ° C n-heptane boiling point: 98.4 ° C water boiling point: 100 ° C pressure: normal pressure (atmospheric pressure) heating medium: heated steam (141 ° C)

As a result of drying the SPG under the above conditions, scaling is suppressed, and the dry SP has a water content of 0.1% by weight or less.
I was able to obtain G.

Comparative Example 1 Using the dryer shown in FIG. 2, SPG powder moistened with n-heptane / water was dried under the following conditions. Introducing speed of wet powder: 172 kg per hour Stirring rotational speed: 190 revolutions per minute Fluidizing means: Paddle blade rotating around an axis Vent gas: Nitrogen gas aeration rate: 40 m ^{3 /} h (standard state) SPG melting point: 192-192 198 ° 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.)

The SPG was dried under the above conditions, but the thickness was 5 m.
Scaling of about m is recognized on the inner wall of the dryer, and moisture is reduced to 1
Only SPG powder containing 1 to 13 wt% was obtained.

The overall heat transfer coefficient of the inner wall of the dryer during the drying of Examples 1, 2 and Comparative Example 1 was measured. The results are shown in the table below. It can be seen that in Example 1 and Example 2, the overall heat transfer coefficient was improved to about twice that in Comparative Example 1.

Overall heat transfer coefficient Example 1 108 kcal / m ² · hr · ° C Example 2 107 kcal / m ² · hr · ° C Comparative Example 1 45 kcal / m ² · hr · ° C

[0020]

According to the present invention, the scaling formed on the inner wall of the dryer is suppressed, and the dry SPG powder is efficiently produced.

[Brief description of drawings]

FIG. 1 is a schematic view 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.

[Explanation of symbols]

1 ・ ・ Dryer 2 ・ ・ Wet powder inlet 3 ・ ・ Dry powder outlet 4 ・ ・ Jacket 5 ・ ・ Heating medium inlet 6 ・
.Fluidizing means, 7 ... exhaust port, 8 ... condenser, 9
..Blowers, 10 ... Heating medium outlets, 11 ... Heat exchangers for circulating gas heating, M..Mixing motors

Claims (6)

[Claims] 1. At least a solvent-moistened 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,
An inlet for 4,8,10-tetraoxaspiro [5,5] undecane powder and dried 3,9-bis (1,1-
Dimethyl-2-hydroxyethyl) -2,4,8,10
The boiling point of the solvent (° C.) using a dryer having an outlet for tetraoxaspiro [5,5] undecane powder, means for fluidizing the wet powder, and a jacket on the outer wall of the dryer.
[When the powder charged into the charging port 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 (° C.) of the solvent, and the powder charged into the charging port is When moistened with a plurality of solvents having an azeotropic composition, the highest temperature of the boiling points of the plurality of solvents is compared with the azeotropic point of the plurality of solvents, and the higher temperature is taken as the boiling point (° C.) of the solvent] to about 190 Drying 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4, characterized in that the wet powder is indirectly heated by passing a heating medium in the temperature range of ° C through the jacket. Method for producing 8,10-tetraoxaspiro [5,5] undecane. 2. The fluidizing means is a wing or a pin.
The method described in. 3. The method according to claim 1, wherein the fluidizing means causes the dryer itself to rotate or vibrate. 4. The method according to claim 1, wherein the drying is performed while aeration or circulation of an air flow. 5. The method according to claim 1, which is dried under reduced pressure. 6. The method according to claim 1, wherein the heating medium has a temperature higher than the boiling point of the solvent by 15 ° C. or more.