JP5065550B2 - Preservation method of oxetane compound - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for stably storing an oxetane compound useful as a material for a cationic curable resin.
[0002]
[Prior art]
Conventionally, there is no known method for stably storing an oxetane compound at room temperature for a long period of time.
For example, trimethylene oxide (oxetane) is stored as a refrigerated product at 2 to 10 ° C. in the dark (in the dark), but no method for stably storing it at room temperature for a long time is known. In addition, for 3-alkyl-3-hydroxymethyloxetane such as 3-ethyl-3-hydroxymethyloxetane, problems such as formation of oligomeric cloudy components occur after long-term storage for about 3 months at room temperature. There is no known effective storage method.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a method capable of stably storing an oxetane compound at room temperature for a long period of time.
[0004]
[Means for Solving the Problems]
The object of the present invention is solved by a method for storing an oxetane compound in which the oxetane compound is stored in an atmosphere of nitrogen, helium, argon, or a mixed gas thereof .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the oxetane compound include trimethylene oxide (oxetane) and trimethylene oxide (oxetane) such as 3-alkyl-3-hydroxymethyloxetane such as 3-methyl-3-hydroxymethyloxetane and 3-ethyl-3-hydroxymethyloxetane. ) A compound having a ring. In the present invention, among these, the aforementioned 3-alkyl-3-hydroxymethyloxetane is preferably used. This alkyl group may have a substituent (hydroxyl group, halogen atom, etc.), and may have an unsaturated bond (double bond, etc.) in its carbon chain. As an alkyl group, a C1-C6 alkyl group is mentioned preferably.
[0006]
Oxetane compounds such as 3-alkyl-3-hydroxymethyloxetane are described in J. Org. Am. Chem. Soc. 79, 3455 (1957), a triol compound and a dialkyl carbonate are subjected to a transesterification reaction in the presence of a catalyst to produce a corresponding cyclic carbonate, and this cyclic carbonate is further thermally decomposed (decarboxylated) to correspond. An oxetane compound is produced and then produced by distillation purification. At this time, the temperature of the transesterification reaction is preferably 50 to 200 ° C., more preferably 70 to 150 ° C., and particularly preferably 80 to 130 ° C., and the temperature of the decarboxylation reaction is 100 to 300 ° C., more preferably 150 to 250 ° C. It is preferable that it is a range of 170 degreeC, especially 170-220 degreeC.
[0007]
By this method, the purity by gas chromatography is 90% or more, the water content is 0.5% by weight or less, the pH is 4.0 to 7.0, the acid value is 0.5 mg NaOH / g or less, and the gas chromatography Purity of 95% or more, moisture content of 20 to 1000 ppm by weight, pH of 5.5 to 6.5, acid value of 0.01 to 2 mg NaOH / g, especially purity by gas chromatography of 98% or more (among others) In particular, an oxetane compound having a water content of 20 to 200 ppm by weight, a pH of 5.5 to 6.5, and an acid value of 0.01 to 0.1 mg NaOH / g can be obtained. it can. In the present invention, the oxetane compound having such physical properties produced by the above method is preferably used.
The purity by gas chromatography was expressed as an area percentage (under the conditions described later), and the acid value was expressed as a NaOH titration value per 1 g of sample. The pH was measured by diluting the sample with pure water to 10% by weight.
[0008]
In the above method, as the triol compound, 1,1,1-trimethylolalkane such as 1,1,1-trimethylolethane and 1,1,1-trimethylolpropane (the carbon number of the alkane is preferably 2 to 2). 6), 1,2,6-hexanetriol, 1,2,4-butanetriol, and the like. As the dialkyl carbonate, those having a lower alkyl group having 1 to 4 carbon atoms are preferable, and dimethyl carbonate is more preferable among them.
[0009]
Examples of the catalyst for transesterification include alkali metal alcoholates (sodium methoxide, potassium methoxide, etc.), alkali metal carbonates (lithium carbonate, sodium carbonate, potassium carbonate, etc.), alkali metal hydroxides (water Lithium oxide, sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal alcoholates (magnesium methoxide, etc.), alkaline earth metal carbonates (magnesium carbonate, etc.), alkaline earth metal hydroxides (hydroxide) Magnesium), aliphatic tertiary amines (triethylamine, tributylamine, etc.), aliphatic ammonium salts (tetramethylammonium bromide, tetrabutylammonium bromide, etc.) and the like are used. The amount used is preferably 0.00001 to 0.1 times mol, more preferably 0.00005 to 0.01 times mol, and particularly preferably 0.0001 to 0.05 times mol for the triol compound.
[0010]
The storage method of the present invention, oxetane compounds, nitrogen, helium, argon or a mixed gas atmosphere thereof, i.e., the liquid level upper space in the container is nitrogen, helium, are substituted with argon or mixed gas thereof ( However, liquid vapor is present) and the solution is stored in a state where dissolved carbon dioxide in the liquid is removed. At this time, the oxetane compound is preferably stored in a sealed state or in a state where intrusion of outside air is blocked in the container, and further preferably stored under light shielding (in a dark place). The storage temperature may be room temperature or lower, but practically room temperature is preferred.
[0011]
As the gas used in the present invention , nitrogen, helium, or argon is used singly or in plural. Among them, nitrogen gas is practically preferable because it is inexpensive. Note that nitrogen, helium, argon, or a mixed gas thereof preferably has an oxygen content of 5 ppm by volume or less and a moisture content at which the dew point is -65 ° C or less.
[0012]
As a specific method for storing the oxetane compound in an atmosphere of nitrogen, helium, argon or a mixed gas thereof , for example, in the production method of the oxetane compound, the pressure set during distillation purification of the generated oxetane compound is used. nitrogen without affecting the (degree of reduced pressure), helium, conducting argon or mixed gas thereof into distillate in the liquid in the tank, mixing the liquid level headspace nitrogen, helium, argon or their tank There is a method of replacing with gas (however, distillate vapor and liquid vapor exist), removing carbon dioxide gas generated by decarboxylation and dissolved in the liquid, and storing in the tank.
[0013]
Further, in the above method for producing an oxetane compound, after distillation purification, nitrogen, helium, argon or a mixed gas thereof is blown into the liquid in the distillate tank and / or the product tank, and the liquid level in the tank is increased. A method of replacing the space with nitrogen, helium, argon or a mixed gas thereof (where liquid vapor exists) and removing dissolved carbon dioxide in the liquid and storing it in the tank is also a storage method of the present invention. Can be mentioned. In this case, the blowing amount of nitrogen, helium, argon or a mixed gas thereof may be 10 volume times or more, preferably about 10 to 200 volume times the liquid surface upper space volume in the tank. However, when the space volume is 5% or less of the liquid volume, the blowing amount may be about 5 to 100 times the liquid volume. Moreover, when it preserve | saves in containers other than a distillate tank or a product tank after distillation refinement | purification, it can preserve | save similarly as nitrogen, helium, argon, or those mixed gas atmosphere. Also in these methods, as described above, the storage of the oxetane compound is preferably performed in a sealed state or in a state where intrusion of outside air is blocked in the container, and further preferably performed in the dark (in a dark place). .
[0014]
In this way, a stabilized oxetane compound that can be stably stored for a long period of time at room temperature can be obtained. That is, the space above the liquid surface in the container is replaced with nitrogen, helium, argon, or a mixed gas thereof (however, liquid vapor is present) and the dissolved carbon dioxide gas in the liquid is removed. Stabilized oxetane compound in a sealed state or a state where intrusion of outside air is blocked, in particular, the upper space on the liquid surface in the container is replaced with nitrogen, helium, argon or a mixed gas thereof (provided that liquid vapor exists) In addition, the dissolved carbon dioxide gas in the liquid is removed, and a stabilized oxetane compound that is shielded from light in a sealed state or a state in which intrusion of outside air is blocked can be obtained.
[0015]
In the preservation method of the present invention, as described above, the oxetane compound can be obtained simply by preserving in an atmosphere of nitrogen, helium, argon or a mixed gas thereof (including a sealed state or a state where intrusion of outside air is blocked, or under light shielding). Although it can be stably stored, a basic compound may be further present in the oxetane compound and stored as an oxetane composition under the gas atmosphere. As the basic compound, a basic alkali metal compound, a basic alkaline earth metal compound, a nitrogen-containing organic basic compound, or the like is used. The concentration when the basic compound is present is preferably in the range of 1 to 1 wt%, more preferably 10 to 1000 wt ppm, and particularly preferably 20 to 500 wt ppm with respect to the oxetane compound. In addition, a basic compound may be used individually or may be used in multiple.
[0016]
Examples of the basic alkali metal compound include alkali metal hydroxides (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonates (lithium carbonate, sodium carbonate, potassium carbonate, etc.), alkali metals. Alcoholate (sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, etc.).
[0017]
Examples of the basic alkaline earth metal compound include alkaline earth metal hydroxides (magnesium hydroxide, calcium hydroxide, etc.), alkali metal carbonates (magnesium carbonate, calcium carbonate, etc.), and alkali metals. Alcoholate (magnesium methoxide, etc.).
[0018]
Examples of the nitrogen-containing basic compound include aliphatic tertiary amines (trialkylamines having an alkyl group having 1 to 6 carbon atoms such as trimethylamine, triethylamine, tripropylamine, tributylamine), aliphatic ammonium salts (tetramethylamine). And tetraalkylammonium halides having an alkyl group having 1 to 6 carbon atoms such as ammonium chloride, tetramethylammonium bromide, tetraethylammonium chloride, and tetraethylammonium bromide). In addition, aliphatic secondary amines (dialkylamines having 1 to 6 carbon atoms such as dimethylamine, diethylamine, dipropylamine, dibutylamine), aliphatic primary amines (methylamine, ethylamine, propylamine, butylamine) And monoalkylamines having a C 1-6 alkyl group such as Furthermore, cyclic amines containing a nitrogen atom in the ring structure (morpholine, piperidine, pyridine, methylpyridine, dimethylaminopyridine, etc.) can also be mentioned. Ammonia itself can also be used.
[0019]
As a specific method for storing an oxetane compound in an atmosphere of nitrogen, helium, argon or a mixed gas thereof and in the presence of a basic compound, for example, in the above-described method for producing an oxetane compound, distillation purification of the produced oxetane compound is performed. during nitrogen without affecting the pressure (vacuum degree) set, helium, conducting argon or mixed gas thereof into the liquid in the distillate tank, the gas above the liquid surface space in the tank (However, fractional vapor and liquid vapor are present) and carbon dioxide gas generated by decarboxylation and dissolved in the liquid is removed (that is, under an atmosphere of nitrogen, helium, argon or a mixed gas thereof) And then, the basic compound is added to the liquid in the distillate tank and stored in the tank.
[0020]
Further, in the above method for producing an oxetane compound, after distillation purification, nitrogen, helium, argon or a mixed gas thereof is blown into the liquid in the distillate tank and / or the product tank, and the liquid level in the tank is increased. The space is replaced with nitrogen, helium, argon, or a mixed gas thereof (however, liquid vapor is present) and dissolved carbon dioxide in the liquid is removed (ie, under an atmosphere of nitrogen, helium, argon, or a mixed gas thereof) Then, a method of adding the basic compound into the liquid of the distillate tank and / or the liquid of the product tank and storing it in the tank is also mentioned as the storage method of the present invention. In addition, when it is stored in a container other than the distillate tank or product tank after distillation purification, it can be stored in an atmosphere of nitrogen, helium, argon or a mixed gas thereof, and in the presence of a basic compound as described above. it can.
[0021]
In this way, a stabilized oxetane composition that can be stably stored at room temperature for a long period of time can be obtained. That is, the space above the liquid level in the container is replaced with nitrogen, helium, argon, or a mixed gas thereof (however, liquid vapor exists) and the dissolved carbon dioxide in the liquid is removed, A stabilized oxetane composition which is in a sealed state or in a state where intrusion of outside air is blocked and contains a basic compound,
[0022]
In particular, the space above the liquid surface in the container is replaced with nitrogen, helium, argon, or a mixed gas thereof (however, liquid vapor exists) and the dissolved carbon dioxide in the liquid is removed, Thus, it is possible to obtain a stabilized oxetane composition which is sealed or in a state where the intrusion of outside air is blocked and which is protected from light and contains a basic compound. The concentration of the basic compound in these stabilized oxetane compositions is the same as described above, and is in the range of 1 ppm by weight to 1% by weight, more preferably 10 to 1000 ppm by weight, particularly 20 to 500 ppm by weight with respect to the oxetane compound. It is preferable.
[0023]
【Example】
Next, the present invention will be specifically described with reference to examples and comparative examples. The following operations were performed under normal pressure unless otherwise specified, and analysis was performed by gas chromatography.
[0024]
Reference example 1
Trimethylolpropane (12.0 mol) and dimethyl carbonate (12.0 mol) were added to a 5 L four-necked flask equipped with a stirrer, thermometer, old show (30 mmφ × 20 stages) and a nozzle for nitrogen sealing. And potassium carbonate (0.006 mol) were added and the temperature was raised to 85 ° C. with stirring. While extracting methanol as a by-product together with azeotropic dimethyl carbonate, after reacting at the same temperature for 1 hour, dimethyl carbonate (4.8 mol) was supplied over 4 hours, and by-product methanol was similarly extracted. The reaction continued. During this time, the reaction temperature gradually increased, but was maintained at 120 ° C. or lower.
[0025]
After completing the supply of dimethyl carbonate, the pressure was gradually reduced to 0.005 MPa, and low boiling substances (unreacted dimethyl carbonate and residual methanol) were extracted. Subsequently, the pressure was returned to normal pressure, the liquid temperature was raised to 200 ° C., and decarboxylation was performed by heating at this temperature for 5 hours.
After completion of decarboxylation, the reaction solution was distilled under a reduced pressure of 0.001 to 0.005 MPa to obtain 1 kg of 3-ethyl-3-hydroxymethyloxetane (hereinafter abbreviated as EHO). This EHO was colorless and transparent, and the transmissivity was 99.5%. The purity by gas chromatography was 99.8%, the water content was 70 ppm by weight, the pH was 6.1, and the acid value was 0.02 mg NaOH / g.
[0026]
The light transmittance was measured with a spectrophotometer at a wavelength of 600 nm for 100 g obtained by dissolving 1 g of a sample in ion-exchanged water. The moisture content was measured with a Karl Fischer moisture meter, the pH was measured by diluting the sample with pure water to 10% by weight, and the acid value was measured by titrating the sample with 0.01 N NaOH.
[0027]
Purity by gas chromatography was expressed as an area percentage obtained from analysis under the following conditions.
Column: Capillary column TC-1, 30m × 0.53φ
Column temperature: 80-240 ° C. (temperature rise at 4 ° C./min)
Injection temperature: 330 ° C
Detector: FID (330 ° C)
Carrier gas: He, 40 ml / min
[0028]
Example 1
100 ml of high-purity nitrogen gas (manufactured by Nippon Oxygen) was blown into a 1 kg solution of the oxetane compound (EHO) obtained in Reference Example 1 through a glass tube at a flow rate of 1 L / min for 15 minutes and then dried in a nitrogen atmosphere. 100 ml each of the oxetane compound was dispensed into 5 glass sample bottles, stoppered (sealed), and stored in the dark at room temperature.
When the preserved sample was taken out after 3 months, all five remained colorless and transparent, and the transmissivity was 99.3 to 99.8%. The pH of this sample was 4.5 to 5.0, and the acid value was 0.03 to 0.05 mg NaOH / g.
[0029]
Comparative Example 1
In Example 1, the sample was stored in the same manner as in Example 1 except that nitrogen gas was not blown and the operation was not performed in a nitrogen atmosphere.
When the preserved sample was taken out after 3 months, all of the 5 samples were cloudy and the transmissivity was 95.2-96.1%. The pH of this sample was 3.6 to 4.0, and the acid value was 0.10 to 0.20 mg NaOH / g, indicating a considerable change.
[0030]
Example 2
In Example 1, when 100 ml of the oxetane compound was separated into a glass sample bottle under a nitrogen atmosphere, the same procedure as in Example 1 was carried out except that triethylamine was added to 50 ppm by weight. There was no cloudiness even after 7 months.
[0031]
【Effect of the invention】
According to the present invention, a special effect is achieved that the oxetane compound can be stably stored for a long period of time at room temperature. That is, according to the present invention, the oxetane compound does not become cloudy and can be stored stably at room temperature for a long period of time (for example, maintaining a light transmittance of 99% or more).

Claims (5)

In the oxetane compound liquid, nitrogen, helium, argon or a mixed gas thereof is conducted to replace the upper space of the liquid surface with the same gas, and the dissolved carbon dioxide gas in the liquid is removed, and under the same gas atmosphere. A method for preserving an oxetane compound, characterized by comprising:
Oxetane compounds
(I) 3-alkyl-3-hydroxymethyl produced by subjecting a triol compound and a dialkyl carbonate to a transesterification reaction in the presence of a catalyst to produce a corresponding cyclic carbonate, and further thermally decomposing (decarboxylating) the cyclic carbonate. An oxetane compound, or
(ii) produced by a method in which a triol compound and a dialkyl carbonate are transesterified in the presence of a catalyst to produce a corresponding cyclic carbonate, which is further pyrolyzed (decarboxylated), and then purified by distillation. A 3-alkyl-3-hydroxymethyloxetane compound,
A method for preserving oxetane compounds .   The method for storing an oxetane compound according to claim 1, wherein the oxetane compound is stored in a sealed state or in a state where intrusion of outside air is blocked in the container.   Furthermore, the preservation | save method of the oxetane compound of Claim 1 or 2 which makes a base compound exist and preserve | saves an oxetane compound. The method of passing nitrogen, helium, argon or a mixed gas thereof into the liquid of the oxetane compound is a method in which nitrogen, helium, argon or a mixed gas thereof is added to the liquid in the distillate tank during the distillation purification of the oxetane compound . the storage method is a method for conducting, according to claim 1 o Kisetan compounds described. A method of passing nitrogen, helium, argon or a mixed gas thereof into a liquid of an oxetane compound is a method in which nitrogen, helium, argon or a mixed gas thereof is distilled into a distillate tank and / or a product after distillation purification of the oxetane compound. The method for preserving an oxetane compound according to claim 1, which is a method of conducting into a liquid in a tank.