JP2000327673A - Preservation of oxetane compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably preserve an oxetane compound useful as a material, etc., for cationic curable resins by preserving the oxetane compound in an atmosphere of an inert gas (except CO2). SOLUTION: An oxetane compound such as a 3-alkyl-3-hydroxymethyloxetane is preserved in a hermetically sealed state or a state in which the infiltration of the outside air is shut off preferably in a container preferably at room temperature in an atmosphere of an inert gas (e.g. nitrogen gas) except gaseous carbon dioxide. Further, a basic compound (e.g. triethylamine) in an amount within the range of preferably 1 wt. ppm to 1% may be present for the above preservation An oxetane compound having >=90% purity (according to a gas chromatography), <=0.5 wt.% moisture content, pH 4.0-7.0 and <=0.5 mgNaOH/g acid value is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for stably storing an oxetane compound useful as a material for a cationically curable resin.

[0002]

2. Description of the Related Art Heretofore, there has been 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. under light shielding (in a dark place), but there is no known method for long-term stable storage at room temperature. Also, with respect to 3-alkyl-3-hydroxymethyloxetane such as 3-ethyl-3-hydroxymethyloxetane, if long-term storage of about 3 months is performed at room temperature, problems such as generation of oligomer-like cloudy components may occur. There is no known effective storage method.

[0003]

An object of the present invention is to provide a method for stably storing an oxetane compound at room temperature for a long period of time.

[0004]

The object of the present invention is attained by a method for storing an oxetane compound in which the oxetane compound is stored in an atmosphere of an inert gas (excluding carbon dioxide gas).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As oxetane compounds, trimethylene oxide (oxetane), 3-methyl-3-
Compounds having a trimethylene oxide (oxetane) ring such as 3-alkyl-3-hydroxymethyloxetane such as hydroxymethyloxetane and 3-ethyl-3-hydroxymethyloxetane are exemplified. In the present invention,
Among them, the above-mentioned 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. Preferred examples of the alkyl group include an alkyl group having 1 to 6 carbon atoms.

Oxetane compounds such as 3-alkyl-3-hydroxymethyloxetane are described in J. Am. Am. Ch
em. Soc. , 79, 3455 (1957), a corresponding cyclic carbonate is produced by a transesterification reaction of a triol compound and a dialkyl carbonate in the presence of a catalyst, and the cyclic carbonate is thermally decomposed (decarbonated). Generating an oxetane compound,
Then, it is produced by a method of purifying by distillation. At this time,
The temperature of the transesterification reaction is 50-200 ° C.
The temperature is preferably in the range of 150 to 150 ° C, particularly 80 to 130 ° C, and the temperature of the decarboxylation reaction is preferably in the range of 100 to 300 ° C, more preferably 150 to 250 ° C, particularly preferably 170 to 220 ° C.

According to 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, and the acid value is 0.5 mg NaOH.
/ G or less, further, the purity by gas chromatography is 95% or more, the water content is 20 to 1000 ppm by weight,
pH 5.5 to 6.5, acid value 0.01 to 2 mg NaO
H / g, especially 9 by gas chromatography.
8% or more (especially 98.0 to 99.9%), water content of 20 to 200 ppm by weight, pH of 5.5 to 6.5,
An oxetane compound having an acid value of 0.01 to 0.1 mg NaOH / g can be obtained. In the present invention, an oxetane compound having such properties, which is produced by the above method, is preferably used. In addition, the purity by gas chromatography was represented by the area percentage (under the conditions described later), and the acid value was represented by the NaOH titration value per 1 g of the sample. The pH was measured by diluting the sample with pure water to 10% by weight.

In the above method, the triol compound may be 1,1,1-trimethylolethane, 1,1,1
1,1,1-trimethylolalkane such as 1-trimethylolpropane (the alkane preferably has 2 to 6 carbon atoms)
), 1,2,6-hexanetriol,
2,4-butanetriol and the like are used. As the dialkyl carbonate, those having a lower alkyl group having 1 to 4 carbon atoms are preferable, and among them, dimethyl carbonate is more preferable.

Further, as a catalyst for the transesterification reaction,
Alcoholates of alkali metals (sodium methoxide,
Potassium metal methoxide), alkali metal carbonate (lithium carbonate, sodium carbonate, potassium carbonate, etc.), alkali metal hydroxide (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal alcoholate (Eg, magnesium methoxide), alkaline earth metal carbonate (eg, magnesium carbonate), alkaline earth metal hydroxide (eg, magnesium hydroxide), aliphatic tertiary amine (eg, triethylamine, tributylamine, etc.), and aliphatic At least one ammonium salt (tetramethylammonium bromide, tetrabutylammonium bromide, etc.) is used. The amount used is 0.00001 to 0.1 times mol, more preferably 0.000 mol per mol of the triol compound.
It is preferably from 0.05 to 0.01 times, more preferably from 0.0001 to 0.05 times.

In the storage method of the present invention, the oxetane compound is replaced with an inert gas (except for carbon dioxide) in an atmosphere of an inert gas (excluding carbon dioxide), that is, the space above the liquid surface in the container is replaced with inert gas except for carbon dioxide. (However, liquid vapor exists)
It is stored in a state where dissolved carbon dioxide in the liquid has been removed. At this time, the oxetane compound is preferably stored in a sealed state in the container or in a state where the invasion of the outside air is blocked, and more preferably in a light-shielded (dark place).
The storage temperature may be room temperature or lower temperature, but room temperature is practically preferable.

As the inert gas, nitrogen, helium, argon or the like is used alone or in combination. Among them, nitrogen gas is practically preferable because it is inexpensive. The inert gas preferably has an oxygen content of 5 ppm by volume or less and a moisture content of a dew point of -65 ° C. or less.

As a specific method for storing the oxetane compound in an inert gas atmosphere, for example, in the above-mentioned method for producing an oxetane compound, a pressure (degree of reduced pressure) set during distillation and purification of the generated oxetane compound is used. The inert gas is conducted into the liquid in the distillate tank within a range that does not affect the temperature, and the space above the liquid surface in the tank is replaced with the inert gas (however, fraction vapor and liquid vapor are present) A method of removing carbon dioxide gas generated by decarboxylation and dissolved in the liquid and storing the gas in the tank.

Further, in the above method for producing an oxetane compound, after the distillation and purification, an inert gas is blown into the liquid in the distillate tank and / or the product tank to inactivate the space above the liquid level in the tank. The storage method of the present invention also includes a method of replacing with a gas (however, liquid vapor is present) and removing the dissolved carbon dioxide gas in the liquid and storing the gas in the tank. In this case, the blowing amount of the inert gas is 10 times or more the volume of the space above the liquid surface in the tank, preferably 10 to 10 times.
It may be about 200 times the capacity. However, when the volume of the space is 5% or less of the liquid volume, the blowing amount may be about 5 to 100 times the liquid volume. Also, when the product is stored in a container other than the distillate tank or the product tank after the distillation and purification, it can be stored in an inert gas atmosphere in the same manner. Also in these methods, as described above, the storage of the oxetane compound is preferably performed in a sealed state in a container or in a state in which the invasion of the outside air is blocked, and further preferably performed under light shielding (dark place). .

Thus, a stabilized oxetane compound which can be stably stored at room temperature for a long period of time can be obtained. That is, the space above the liquid surface in the container is replaced with an inert gas (however, excluding carbon dioxide gas) (however, liquid vapor is present), and the dissolved carbon dioxide gas in the liquid is removed. The stabilized oxetane compound in a sealed state or in a state where the invasion of the outside air is shut off, in particular, the space above the liquid surface in the container is replaced with an inert gas (excluding carbon dioxide gas) (however, liquid vapor And 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 in a state where the invasion of outside air is blocked in the container can be obtained.

In the storage method of the present invention, the oxetane compound can be stably stored only by storing in an inert gas atmosphere (including a sealed state or a state in which the invasion of outside air is blocked or under light shielding) as described above. However, the oxetane compound may be preserved by further allowing a basic compound to be present in the oxetane compound under the inert 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 of the basic compound in the presence of the oxetane compound is 1 ppm by weight to 1% by weight, preferably 10 to 1000 ppm by weight, more preferably 20 to 5% by weight.
It is preferably in the range of 00 ppm by weight. The basic compound may be used alone or in combination.

Examples of the basic alkali metal compound include alkali metal hydroxides (such as lithium hydroxide, sodium hydroxide and potassium hydroxide) and alkali metal carbonates (such as lithium carbonate, sodium carbonate and potassium carbonate). And alkali metal alcoholates (sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, etc.).

Examples of the basic alkaline earth metal compound include alkaline earth metal hydroxides (eg, magnesium hydroxide and calcium hydroxide) and alkali metal carbonates (eg, magnesium carbonate and calcium carbonate). And alkali metal alcoholates (eg, magnesium methoxide).

Examples of the nitrogen-containing basic compound include aliphatic tertiary amines (trimethylamine, triethylamine,
1 to 1 carbon atoms such as tripropylamine and tributylamine
Trialkylamines having 6 alkyl groups), aliphatic ammonium salts (tetramethylammonium chloride,
And tetraalkylammonium halides having an alkyl group having 1 to 6 carbon atoms, such as tetramethylammonium bromide, tetraethylammonium chloride, and tetraethylammonium bromide. Further, aliphatic secondary amines (dialkylamines having an alkyl group having 1 to 6 carbon atoms such as dimethylamine, diethylamine, dipropylamine, dibutylamine, etc.) and aliphatic primary amines (methylamine, ethylamine, propylamine, butylamine) Monoalkylamine having an alkyl group having 1 to 6 carbon atoms). 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.

As a specific method of storing the oxetane compound in an inert gas atmosphere and in the presence of a basic compound, for example, in the above-mentioned method for producing an oxetane compound, the oxetane compound produced may be purified by distillation. Inert gas is conducted into the liquid in the distillate tank within a range that does not affect the set pressure (degree of decompression), and the space above the liquid surface in the tank is replaced with inert gas (however, distillate vapor or Liquid vapor is present), and at the same time, remove the carbon dioxide gas generated by the decarboxylation and dissolved in the liquid (that is, under an inert gas atmosphere), and then remove the basic compound in the liquid in the distillate tank. And storing in the tank.

Further, in the above method for producing an oxetane compound, after distillation and purification, an inert gas is blown into the liquid in the distillate tank and / or the product tank to make the space above the liquid level in the tank inert. While displacing with gas (however, liquid vapor is present), dissolved carbon dioxide gas in the liquid is removed (that is, under an inert gas atmosphere), and then a basic compound is removed from the liquid in the distillate tank and into the distillate tank. A method of adding to the liquid in the product tank and storing in the tank is also included as the storage method of the present invention. In addition, when the product is stored in a container other than the distillate tank or the product tank after the distillation and purification, it can be stored in an inert gas atmosphere and in the presence of a basic compound as described above.

Thus, a stabilized oxetane compound which can be stably stored at room temperature for a long period of time can be obtained. That is, the space above the liquid surface in the container is replaced with an inert gas (however, excluding carbon dioxide gas) (however, liquid vapor is present), and the dissolved carbon dioxide gas in the liquid is removed. A stabilized oxetane compound which is in a sealed state or in a state where the invasion of outside air is blocked, and contains a basic compound,

In particular, the space above the liquid surface in the container is replaced with an inert gas (however, excluding carbon dioxide) (however, liquid vapor is present) and the dissolved carbon dioxide in the liquid is removed. In addition, a stabilized oxetane compound which is light-shielded in a storage container in a sealed state or in a state where invasion of outside air is blocked, and which contains a basic compound can be obtained. The concentration of the basic compound in the stabilized oxetane compound is the same as described above, and is 1 to 1% by weight, more preferably 10 to 1000% by weight, based on the oxetane compound.
In particular, the content is preferably in the range of 20 to 500 ppm by weight.

[0023]

Next, the present invention will be described specifically with reference to examples and comparative examples. The following operations were performed under normal pressure unless otherwise specified, and the analysis was performed by gas chromatography.

Reference Example 1 Stirrer, thermometer, older show (30 mmφ × 20
Stage) and a 5 L four-neck flask equipped with a nitrogen sealing nozzle were charged with trimethylolpropane (12.0).
Mol), dimethyl carbonate (12.0 mol) and potassium carbonate (0.006 mol), and the temperature was raised to 85 ° C. while stirring. While extracting methanol as a by-product together with azeotropic dimethyl carbonate, 1
After reacting for an hour, dimethyl carbonate (4.8 mol) was supplied over 4 hours, and the reaction was continued while methanol produced as a by-product was similarly extracted. During this time, the reaction temperature gradually increased, but was kept at 120 ° C. or lower.

After the supply of dimethyl carbonate was completed, the pressure was gradually reduced to 0.005 MPa to extract low-boiling substances (unreacted dimethyl carbonate and residual methanol). Next, the pressure was returned to normal pressure, the liquid temperature was raised to 200 ° C., and the mixture was heated at this temperature for 5 hours to perform decarbonation. After completion of decarboxylation, the reaction solution was distilled under 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 had a light transmittance of 99.5%.
The purity by gas chromatography is 99.8.
%, Water content 70 ppm by weight, pH 6.1, acid value 0.02 mg NaOH / g.

The transmittance was measured at a wavelength of 600 nm using a spectrophotometer on a sample obtained by dissolving 1 g of a sample in ion-exchanged water to make 100 g. The water 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 determined by measuring the sample by 0.01.
It was determined by titration with N-NaOH.

The purity by gas chromatography was represented by the area percentage obtained from the analysis under the following conditions. Column: Capillary column TC-1, 30m × 0.5
3φ Column temperature: 80 to 240 ° C (heating at 4 ° C / min) Injection temperature: 330 ° C Detector: FID (330 ° C) Carrier gas: He, 40 ml / min

Example 1 1 kg of the oxetane compound (EHO) obtained in Reference Example 1
After blowing high-purity nitrogen gas (manufactured by Nippon Sanso Corporation) at a flow rate of 1 L / min for 15 minutes through a glass tube into the liquid of the above, the oxetane compound was placed in five dried 100 ml glass sample bottles under a nitrogen atmosphere. Aliquots of 100 ml were made, stoppered (closed) and stored in the dark at room temperature.
After 3 months, the preservation sample was taken out, and all five samples remained colorless and transparent, and the light transmittance 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.

Comparative Example 1 A sample was stored in the same manner as in Example 1 except that no nitrogen gas was blown and the operation was not performed under a nitrogen atmosphere. When the stored sample was taken out three months later, all of the five samples were cloudy and had a light transmittance of 95.2.
９６96.1%. The pH of this sample was 3.6 to 4.0, and the acid value was 0.10 to 0.20 mg NaO.
H / g was observed and a considerable change was observed.

Example 2 Example 1 was carried out in the same manner as in Example 1 except that 100 ml of the oxetane compound was added to a glass sample bottle under a nitrogen atmosphere so that 50 ppm by weight of triethylamine was added. . No cloudiness was observed even after 7 months.

[0031]

According to the present invention, a special effect that the oxetane compound can be stably stored at room temperature for a long period of time is achieved. That is, according to the present invention, the oxetane compound can be stably stored at room temperature for a long period of time (for example, maintaining a light transmittance of 99% or more) without clouding.

Claims (9)

[Claims] An oxetane compound is converted into an inert gas (however,
A method for storing an oxetane compound, which is stored in an atmosphere (excluding carbon dioxide). 2. The method for storing an oxetane compound according to claim 1, wherein the oxetane compound is stored in a container in a sealed state or in a state where invasion of outside air is blocked. 3. The oxetane compound is stored under light shielding.
A method for preserving an oxetane compound according to claim 1. 4. The purity by gas chromatography is 9
0% or more, water content 0.5% by weight or less, pH 4.0
The method for storing an oxetane compound according to claim 1, wherein an oxetane compound having an acid value of 0.5 mgNaOH / g or less is used. 5. The oxetane compound is a 3-alkyl-3-
The method for storing an oxetane compound according to any one of claims 1 to 3, wherein the oxetane compound is hydroxymethyl oxetane. 6. The method for storing an oxetane compound according to claim 1, wherein the oxetane compound is stored in the presence of a basic compound. 7. The space above the liquid surface in the container is replaced with an inert gas (excluding carbon dioxide gas), and the dissolved carbon dioxide gas in the liquid is removed. A stabilized oxetane compound in which entry has been blocked. 8. The stabilized oxetane compound according to claim 7, which is protected from light. 9. The composition according to claim 7, which contains a basic compound.
Or the stabilized oxetane compound according to 8.