JPH10175959A - 1,2-dimethylimidazole exhibiting liquid state at normal temperature, its production and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject liquid compound usable as a catalyst for polyurethane resin and a cure accelerator for epoxy resin without using a large amount of solvent by adding oxygen and water to 1,2-dimethylimidazole. SOLUTION: The objective liquid compound is produced by compounding 1,2-dimethylimidazole (A) with usually 0.001-100wt.% (based on the component A) of one or more kinds of oxygen sources selected from oxygen, ozone, air and hydrogen peroxide and 0.001-20wt.% of water. It is preferable to heat the component A together with oxygen and water for liquefying the component A. The amount of the liquid compound is preferably 0.001-20 pts.wt. based on 100 pts.wt. of a polyol for the use as a catalyst for polyurethane and 0.001-20 pts.wt. based on 100 pts.wt. of epoxy resin for the use as a cure accelerator for epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 1,2-dimethylimidazole which is liquid at room temperature, a method for producing the same, and uses thereof.

[0002]

2. Description of the Related Art 1,2-Dimethylimidazole is a crystalline substance at room temperature because it has a melting point of 37-39 ° C.
For this reason, 1,2-dimethylimidazole is desirably heated and melted for use where liquid 1,2-dimethylimidazole is desired, for example, as a catalyst for polyurethane resin or a curing accelerator for epoxy resin. -Dimethyl imidazole diluted with various solvents such as ethylene glycol and water is used.

[0003]

However, 1, 2
-Since dimethylimidazole has good crystallinity, it will crystallize again if left for a while at room temperature even if it is melted by heating. On the other hand, when a solvent is used, a large amount of the solvent is required, which may adversely affect a polyurethane resin, an epoxy resin, and the like, which is not advantageous. Therefore, 1,2-dimethylimidazole which does not require use of a large amount of solvent and exhibits a liquid state at room temperature has been desired.

[0004]

Means for Solving the Problems The present inventors have proposed 1,2-
As a result of intensive studies on the liquefaction method of dimethylimidazole, the liquid 1,2 was prepared without using a large amount of solvent.
-We succeeded in obtaining dimethylimidazole, and found a new fact that liquefied 1,2-dimethylimidazole can be used as a catalyst for polyurethane resins and a curing accelerator for epoxy resins without any adverse effect. The invention has been completed.

That is, the present invention relates to 1,2-dimethylimidazole which is liquid at room temperature, a method for producing the same, and its use.

Hereinafter, the present invention will be described in detail.

In the present invention, in order to liquefy 1,2-dimethylimidazole, 1,2-dimethylimidazole is used.
Add oxygen and water to the tube.

The oxygen is not particularly limited, but includes, for example, diatomic molecular oxygen, oxygen only such as ozone, oxygen containing air such as air, hydrogen peroxide, and the like.
Sodium peroxide, potassium peroxide, benzoyl peroxide, formic acid, peracetic acid, perbenzoic acid, peroxynitrate, periodate, sodium periodate and potassium periodate, etc., which can generate oxygen, etc. Can be Among these, it is preferable to use one or more selected from the group consisting of oxygen, ozone, air, and hydrogen peroxide since no metal oxide, inorganic acid, organic acid, or the like remains after the reaction.

In the method of the present invention, the amount of oxygen to be used is not particularly limited because it varies depending on the type of oxygen.
Usually, it is in the range of 0.001% by weight to 100% by weight. For example, when hydrogen peroxide is used, it is preferably 0.0% by weight.
1% by weight to 10% by weight, more preferably 0.0%
It is in the range of 5% to 1% by weight. If it is less than 0.001% by weight, it may not be liquid, so it is not practical.
If it exceeds 100% by weight, the effect of increasing hydrogen peroxide is small.

In the method of the present invention, the amount of water used is 0.001 to 1,2-dimethylimidazole.
Wt% to 20 wt%, preferably 0.00
In the range of 5% to 10% by weight, more preferably 0.0%
It is in the range of 1% to 5% by weight. If it is less than 0.001% by weight, it may not be liquid, so it is not practical.
If it exceeds 20% by weight, the effect of increasing water is small.

In the method of the present invention, in order to liquefy 1,2-dimethylimidazole, it is preferable to add oxygen and water and heat the mixture. It liquefies without heating, but liquefaction proceeds more rapidly with heating. Alternatively, oxygen and water may be added after 1,2-dimethylimidazole is heated and melted.

In the method of the present invention, the heating temperature is not particularly limited as long as 1,2-dimethylimidazole is melted.

In the method of the present invention, although the cause of liquefaction is not clear, 1,2-dimethylimidazole reacts with oxygen to form N-form of 1,2-dimethylimidazole.
It is considered that an oxide is generated and 1,2-dimethylimidazole is liquefied by adding water thereto.

In the method of the present invention, an inert gas such as a carbon dioxide gas, a nitrogen gas, a helium gas, an argon gas or the like may be present.

When the liquid 1,2-dimethylimidazole of the present invention is used as a catalyst for a polyurethane resin,
The amount used is 0.001 to 20 parts by weight, preferably 0.01 to 10 parts by weight, based on 100 parts by weight of a known polyol. If the amount is less than 0.001 part by weight, unreacted polyol remains, which is not practical. If the amount exceeds 20 parts by weight, the effect of increasing the catalyst is small. In addition, known tertiary amine catalysts and their organic carboxylate salts and organic tin compounds which are usually used as cocatalysts can be used as cocatalysts as long as the catalytic function of the present invention is not lost.

When the liquid 1,2-dimethylimidazole of the present invention is used as a curing accelerator for an epoxy resin, the amount used is 0.001 to 20 parts by weight based on 100 parts by weight of a known epoxy resin. Preferably 0.01 to
10 parts by weight. If the amount is less than 0.001 part by weight, unreacted epoxy resin remains, which is not practical. If the amount exceeds 20 parts by weight, the effect of increasing the catalyst is small.

[0017]

As described above, the liquid 1,2-dimethylimidazole obtained by adding oxygen and water according to the present invention does not precipitate crystals without using a large amount of solvent, and is a liquid polyol, It is excellent in compatibility with epoxy resin and the like, and the physical properties of polyurethane resin and epoxy resin manufactured using liquid 1,2-dimethylimidazole are the same as those using crystalline 1,2-dimethylimidazole. As always, it is industrially significant.

[0018]

EXAMPLES The method of the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 10 g of 1,2-dimethylimidazole (0.104 mol)
To 1), 0.05 g of water was added, and after passing 400 ml of oxygen, the mixture was heated to 60 ° C. to obtain liquefied 1,2-dimethylimidazole. This was stored at 0 to 2 ° C. for 30 days, but no crystals were precipitated.

Example 2 1,2-dimethylimidazole (10 g, 0.104 mol)
To 1), 0.05 g of 31% hydrogen peroxide was added, and the mixture was heated to 60 ° C. to obtain liquefied 1,2-dimethylimidazole. This was stored at 0 to 2 ° C. for 30 days, but no crystals were precipitated.

Example 3 1,2-dimethylimidazole (10 g, 0.104 mol)
To 1), 0.05 g of water and 0.5 g of carbon dioxide were added, and 400 ml of oxygen was aerated. After heating to 60 ° C., liquefied 1,2-dimethylimidazole was obtained. This was stored at 0 to 2 ° C. for 30 days, but no crystals were precipitated.

Comparative Example 1 1,2-dimethylimidazole (10 g, 0.104 mol)
To 1), 0.1 g of water was added, and the mixture was heated to 60 ° C. to obtain liquefied 1,2-dimethylimidazole. This at room temperature
Upon standing overnight, the 1,2-dimethylimidazole solidified.

Comparative Example 2 10 g of 1,2-dimethylimidazole (0.104 mol
To 1), 0.5 g of oxygen was added, and the mixture was heated to 60 ° C. to obtain liquefied 1,2-dimethylimidazole. When this was allowed to stand at room temperature overnight, 1,2-dimethylimidazole solidified.

Example 4 Sucrose polyol (trade name: SU-264,
OH value = 401mgKOH / g, Mitsui Toatsu Chemicals, Inc.
50 parts by weight, aromatic amine-based polyol (trade name:
NT-400, OH value = 401 mgKOH / g, manufactured by Mitsui Toatsu Chemicals, Inc.) 50 parts by weight, foaming agent (trade name: L-5)
340, silicone surfactant, Nippon Unicar Co., Ltd.
1.5 parts by weight, water 4.0 parts by weight, HCFC-141
b (manufactured by Central Glass Co., Ltd.), 20 parts by weight of liquid 1,2-dimethylimidazole 2.6 parts by weight obtained in Example 1, and crude MDI (trade name: MR-200, NC)
O concentration = 31.2%, manufactured by Nippon Polyurethane Industry Co., Ltd.)
The mixture was stirred and mixed at a mixing ratio of 130 parts by weight (formulation), and a foaming test was performed at a mold temperature of 40 ° C. Ten minutes after foam formation, the foam surface was pressed with a finger to evaluate the brittleness of the foam. Further, the center of the formed foam was cut out, and the density and the thermal conductivity were measured. The results were as shown in Table 1.

[0025]

[Table 1]

Comparative Example 3 Foaming was carried out in the same manner as in Example 4 except that 2.6 parts by weight of the crystalline 1,2-dimethylimidazole obtained in Comparative Example 1 was used instead of liquid 1,2-dimethylimidazole. A test was conducted to evaluate the physical properties of the foam and to measure the density and the thermal conductivity. The results were as shown in Table 1.

Example 5 Epoxy resin (trade name: Epikote 828, diglycidyl ether bisphenol A, epoxy equivalent = 187,
100 parts by weight of Yuka Shell Epoxy Co., Ltd., 3-methyltetrahydrophthalic anhydride (trade name: MT-50)
0, manufactured by Nippon Rika Co., Ltd.) and 90 parts by weight of the liquefied 1,2-dimethylimidazole 1.0 obtained in Example 1.
Stir-mixing was performed at a blending ratio of parts by weight. The gelation time at a temperature of 100 ° C. was 1470 seconds. Further, after 2 hours at 100 ° C.,
Curing was performed under the condition of 0 hour, and the heat distortion temperature (HDT) was measured to be 135 ° C. In addition, the measuring method of HDT followed the thermal load deflection test (JISK7207).

Comparative Example 4 The same compounding ratio as in Example 5 was used except that 1.0 part by weight of the crystalline 1,2-dimethylimidazole obtained in Comparative Example 1 was used instead of the liquid 1,2-dimethylimidazole. Stirring was performed. The gelation time at a temperature of 100 ° C. was 1518 seconds. Also, at 100 ° C, 2
After that, curing was further performed at 130 ° C. for 20 hours, and the heat distortion temperature (HDT) was measured to be 134 ° C. In addition, the measuring method of HDT followed the thermal load deflection test (JISK7207).

Claims (7)

[Claims] 1. A 1,2-dimethylimidazole which is liquid at room temperature. 2. A liquid 1,1, which is liquid at ordinary temperature, characterized by adding oxygen and water to 1,2-dimethylimidazole.
A method for producing 2-dimethylimidazole. 3. The method according to claim 2, wherein the oxygen is one or more selected from the group consisting of diatomic molecular oxygen, ozone, air and hydrogen peroxide. 4. The method according to claim 2, wherein the amount of oxygen is 0.001% by weight to 100% by weight based on 1,2-dimethylimidazole. 5. The method according to claim 2, wherein the amount of water is 0.001% by weight to 20% by weight based on 1,2-dimethylimidazole. . 6. A polyurethane resin catalyst comprising 1,2-dimethylimidazole which is liquid at ordinary temperature as an active ingredient. 7. A curing accelerator for epoxy resin containing 1,2-dimethylimidazole which is liquid at room temperature as an active ingredient.