JPH07233137A - Method for producing aliphatic polyisocyanate - Google Patents

Abstract

PURPOSE:To provide a method capable of easily and extremely stably producing an aliphatic polyisocyanate little in unreacted filtration cakes in high yield. CONSTITUTION:A method for producing an aliphatic polyisocyanate comprises simultaneously supplying an aliphatic polyamine and hydrogen chloride gas into an ester solvent and subsequently reacting the produced aliphatic polyamine hydrochloride with phosgene.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an aliphatic polyisocyanate. The aliphatic polyisocyanate produced by the present invention is extremely useful as a polyurethane-based material, a polyurea-based material, and a polyisocyanurate-based material in the fields of chemical industry, resin industry, coating industry, and the like.

[0002]

2. Description of the Related Art Various methods have already been proposed for producing organic isocyanate compounds.

For example, a method of producing a urethane compound from a formamide compound or an amine compound and then thermally decomposing it (JP-A-3-200756), and a method of reacting an alkali cyanate with a chloromethyl group (JP-A-50-
64245), a method of oxidizing a formamide compound at high temperature (JP-A-54-39018), and a method of reacting carbon monoxide with a nitro compound (Issled Obl Kh.
im Vysokomol Soedine Neft
ekhim 1997, 15-16), a method of reacting an organic halogen compound with silver nitrocyanamide (JCS
ParkinTrans I 1988, 2137-
2140) and the like, but a phosgene method of reacting an organic amine with phosgene is typical.

The phosgene method is roughly classified into a direct method in which a starting amine and phosgene are directly reacted and a hydrochloride method in which the starting amine is once converted into a hydrochloride and then reacted with phosgene.

The direct method is much simpler than the hydrochloride method, but the carbamoyl chloride or isocyanate formed reacts with the starting amine to form urea as a by-product. In the case of aromatic isocyanate, generally, also in this direct method, the by-produced urea is further reacted with phosgene to form an isocyanate (Ann. 562, 75 (19).
49), Ber. 17, 1284 (1884)), it is relatively easy to obtain a product in a high yield, which is not a problem.

However, in the case of aliphatic polyisocyanate, the by-product urea reacts with phosgene,
It is known to produce a chlorine derivative as a by-product (Brit. 1
086782), which is usually produced as a by-product in an amount of 3 to 10% and sometimes close to 20%, which lowers the yield and adversely affects the physical properties of the urethane resin used, and thus the direct method is not usually used. Therefore, in the case of an aliphatic polyisocyanate, in order to suppress urea by-produced by phosgenation, the starting amine is made into a hydrochloride in an organic solvent in advance, and then the hydrochloride is produced by reacting with phosgene to produce an isocyanate. The method is widely used.

The present inventors have proposed a method of using an ester solvent as a reaction solvent as a method of suppressing the production of this chlorine derivative (JP-A-3-7253 and JP-A-3-3253).
No. 204851).

[0008]

However, although this method is very excellent as a method for suppressing the chlorine derivative, it is a hydrochloric acid method in which hydrochloric acid gas is charged into an amine solution in which a raw material aliphatic polyamine is dissolved. Therefore, hydrochloric acid gas is not uniformly dispersed, and a large amount of coarse-grained hydrochloride is likely to be generated due to agglomeration of the hydrochlorides, etc., and the majority of the hydrochloride is not stable and cannot be stably obtained. , There was room for improvement.

The coarse-grained aliphatic polyamine hydrochloride is
Crushing is not easy, and almost no crushing is possible with boiling or vigorous stirring. Also, since the contact surface area with phosgene is also small, the reaction rate is significantly reduced,
Since it remains unreacted as it is, the yield may be lowered, and there is a problem that many filter cakes are left after the phosgenation reaction. The decrease in yield is the first problem, but the fact that there are many unreacted filter cakes also poses a serious problem when production is actually started in an actual device. Specifically, the productivity is deteriorated because the time of the filtration step for removing the unreacted filter cake is considerably extended and the complicated filter cake extraction work is increased. As a result, the production amount of aliphatic polyisocyanate is reduced and the cost is increased. In order to avoid this problem, even if the phosgenation reaction is continued for a long time, almost no unreacted salt is reduced, rather, the tar of the produced aliphatic polyisocyanate itself proceeds, and the yield is further increased. Cause decline. The present invention is intended to be an improved invention of the prior application (Japanese Patent Application Laid-Open Nos. 3-7253 and 3-204851), and a method for producing atomized aliphatic polyamine hydrochloride and its hydrochloride. It is a method for producing an aliphatic polyisocyanate in which phosgene is reacted with.

[0010]

Means for Solving the Problems In order to improve the above-mentioned problems, the present inventors have earnestly studied a method for producing an aliphatic polyisocyanate by a hydrochloride method using an ester solvent, and as a result, found to be 500 μm or less. If a fine particle size aliphatic polyamine hydrochloride having 80% or more of hydrochloride is reacted with phosgene, there are few unreacted filter cakes, the yield is high, and the target aliphatic polyisocyanate is easily and extremely stable. I found that it can be manufactured in a simple manner. In addition, the method for making the aliphatic polyamine hydrochloride into such a fine particle diameter is as follows. The method of charging the ester solvent and hydrochloric acid chloride is extremely effective.
Furthermore, they have found that it is more effective if the charged aliphatic polyamine is mixed with an ester solvent, and have reached the present invention.

That is, the present invention is characterized in that an aliphatic polyamine and hydrochloric acid gas are simultaneously charged in an ester solvent to produce an aliphatic polyamine hydrochloride, and then reacted with phosgene. It is a method of manufacturing nato.

In the present invention, the aliphatic polyisocyanate is
It represents a bifunctional or higher organic isocyanate in which an isocyanate group is not directly bonded to an aromatic ring, and includes the following compounds. For example, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate Linear aliphatic polyisocyanate such as nato, m-xylylene diisocyanate, p-xylylene diisocyanate, o-xylylene diisocyanate, or xylylene diisocyanate in which these are arbitrarily mixed, 1,3- Cyclic aliphatic polyimides such as bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, 2,2-bis (4-isocyanatocyclohexyl) propane, bis (isocyanatomethyl) norbornene It is a cyanate and the like. Examples of the aliphatic polyamine include the following compounds. For example, pentamethylenediamine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine,
Linear aliphatic polyamines such as 2,4,4-trimethylhexamethylenediamine, octamethylenediamine, nonamethylenediamine, m-xylylenediamine, p-xylylenediamine, o-xylylenediamine, or any of them. Mixed xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, isophoronediamine, bis (4-aminocyclohexyl) methane, 2,2
-Cyclic aliphatic polyamines such as bis (4-aminocyclohexyl) propane and bis (aminomethyl) norbornene.

As the reaction solvent, an ester solvent is used in order to suppress the chlorine derivative which is a by-product. Of these, fatty acid esters and aromatic carboxylic acid esters are preferable.

Examples of the fatty acid esters include amyl formate, -n-amyl acetate, isoamyl acetate, methyl isoamyl acetate, -n-butyl acetate, isobutyl acetate, 2-ethylbutyl acetate, methoxybutyl acetate, ethoxyethyl acetate. Methoxyethyl acetate, ethyl acetate, secondary hexyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, benzyl acetate, phenyl acetate, methyl carbitol acetate, ethylene glycol diacetate, ethyl propionate, propionate-n- Butyl, isoamyl propionate, ethyl butyrate,
Examples include butyl butyrate, isoamyl butyrate, butyl stearate, butyl lactate, amyl lactate and the like. Examples of aromatic carboxylic acid esters include dimethyl phthalate, methyl benzoate, ethyl benzoate and the like. More preferably, the esters having a boiling point of 120 to 180 ° C. can be used to suppress tarring of the aliphatic polyisocyanate itself due to overheating, and can be easily separated from the aliphatic polyisocyanate by distillation. Is. Regarding the type of the solvent used, each may be used alone or two or more types may be mixed, but from the viewpoint of recovery, the single use is preferable.

In the method of the present invention, the mixing ratio of the aliphatic polyamine and the solvent during the hydrochloric acid salification reaction of the aliphatic polyamine varies depending on the conditions such as the stirring state and the temperature, but generally the weight ratio of the aliphatic polyamine to the solvent is% by weight. Is preferably 3 to 25%, more preferably 5 to 20%. If it exceeds 25%, the salt-forming particle size tends to increase due to a reduction in the dispersion effect, and if it is less than 3%, the volume efficiency deteriorates, which is not industrially advantageous.

Aliphatic polyamine During the hydrochloric acid-chlorination reaction, the charging rate ratio of the aliphatic polyamine and the hydrochloric acid gas is 0.2 to 1.5 in terms of functional group molar ratio (amino group / hydrochloric acid gas), and more preferably 0.
5 to 1.2 (amino group / hydrochloric acid gas) is preferable. 1.5
If it exceeds, the salt-forming particle size tends to be large, and
If it is less than 2, the amount of hydrochloric acid gas used increases, which is not industrially advantageous.

The reaction temperature is 10 to 3 in the hydrochloric acid salification reaction.
It is preferably 0 ° C or lower. If the temperature is 10 ° C. or lower, a refrigerator is required and the equipment cost increases, and if the temperature is 30 ° C. or higher, the salt-forming particle size tends to increase, which is not preferable.
The reaction for phosgenation is 120 to 180 ° C., and further 13
0-160 degreeC is preferable. Although it does not react at 120 ° C. or lower, the reaction rate is slow and not practical, and at 180 ° C. or higher, the aliphatic polyisocyanate itself has no thermal stability, and the yield decreases due to an increase in tar content.

The present invention is under reduced pressure, atmospheric pressure, or
In order to further increase the reaction rate, the reaction can be performed under a pressure higher than atmospheric pressure.

A preferred embodiment of the present invention is as follows.
In a reactor equipped with a reflux condenser, a thermometer, a phosgene blowing tube, a hydrochloric acid blowing tube, a raw material dropping device, a solvent dropping device, and a stirring blade, a solvent, an aliphatic polyamine in the raw material dropping device,
Charge the same solvent into the solvent dropping device. Next, while the hydrochloric acid gas is being blown from the hydrochloric acid blowing pipe, the aliphatic polyamine and the solvent are simultaneously charged and continuously charged to perform hydrochloric acid chlorination. Next, the salt-making mass is heated to a predetermined temperature, and phosgene is blown from the phosgene blowing tube to carry out a reaction. After completion of the reaction, unreacted phosgene and hydrochloric acid are purged with nitrogen, the solvent is removed, and the residue is purified by distillation to obtain the desired aliphatic polyisocyanate.

[0020]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Example 1 A reaction flask equipped with a reflux condenser, a thermometer, a phosgene blowing tube, a hydrochloric acid blowing tube, a raw material dropping device, a solvent dropping device, and a stirring blade, and a solvent flask having an internal volume of 2 l and 1000 g of solvent amyl acetate,
Into the raw material dropping device, 150.0 g (0.961 mol) of bis (aminomethyl) norbornene (hereinafter abbreviated as NBDA),
The remaining solvent, amyl acetate (350 g) was charged into the solvent dropping device (NBDA concentration = 11.1 wt% (to solvent)). Next, while cooling with stirring, the hydrochloric acid gas was removed from the hydrochloric acid blowing tube by 3
At a rate of 5.4 g / H, NBDA and amyl acetate as a solvent in the dropping device were added together at a constant weight ratio of 1: 2.3 at a rate of 250.0 g / H while adding hydrochloric acid gas at the same time. It started and ended in 2 hours. Further, the solution was aged for 0.5 hours while charging hydrochloric acid gas as it was. Also,
These series of salt formation reactions were carried out at an internal temperature of 20 to 30 ° C. Here, the particle size of NBDA hydrochloride is determined by Japan Mining Co., Ltd.
When measured with a process particle size distribution analyzer TSUBUTEC-100, 99.5% of particles of 500 μm or less are 5
Only 0.5% of the particles exceeded 00 μm. Next, after heating the salt-making mass to 135 ° C., phosgene was blown from the phosgene blowing tube at a rate of 100 g / H (1.0 mol / H) to maintain the internal temperature at 130 to 140 ° C. The reaction continued for an hour. After completion of the reaction, unreacted phosgene and hydrochloric acid were purged with nitrogen to remove unreacted NBDA.
After removing 1.3 g (as dry) of hydrochloride by filtration, the filtrate was desolvated and distilled under reduced pressure (1 to 2 mmHg) to obtain 0.1% by weight of chlorine-substituted chloromethylnorbornylmethylisocyanate. Contains bis (isocyanatomethyl)
184.6 g (purity conversion yield = 93.0%) of norbornene (hereinafter abbreviated as NBDi) was obtained. The results are shown in Table 1.

Example 2 The amount of NBDA charged was twice that of Example 1, 300.0 g.
(1.92 mol), and the test was conducted in the same manner as in Example 1. NBDA hydrochloride has a particle size of 98.
At 3%, 1.7% of the particles have a size of more than 500 μm.
The filter cake weighed 3.2 g (as dry) and had a chlorine substitution product of 0.
365.5 g of NBDi containing 1% by weight (purity conversion yield = 92.1%) was obtained. The results are shown in Table 1.

Example 3 The amount of NBDA charged was 75.0 g, which is half of that in Example 1.
(0.480 mol) and tested in the same manner as in Example 1. NBDA hydrochloride has particles of 500 μm or less
At 9.9%, there was only 0.1% of particles above 500 μm. The filter cake was 0.2 g (as dry), and 94.0 g (purity conversion yield = 94.9%) of NBDi containing 0.1% by weight of a chlorine-substituted compound was obtained. The results are shown in Table 1.

Example 4 A test was conducted in the same manner as in Example 1 except that 1350 g of the solvent amyl acetate was charged into a reaction flask and NBDA was directly added dropwise. NBDA hydrochloride has 82.0% of particles of 500 μm or less, and 18.0 particles of 500 μm or more.
%Met. The filter cake weighed 2.9 g (as dry) and contained NBDi183.2 g containing 0.1% by weight of a chlorine-substituted compound.
(Purity conversion yield = 92.3%) was obtained. The results are shown in Table 1.

Comparative Example 1 Solvent amyl acetate 1350 g and NBDA 150.0 (0.
The same test as in Example 1 was conducted except that 961 mol) was initially charged in the reaction flask. In NBDA hydrochloride, 31.2% of particles were 500 μm or less. The filter cake was 85.8 g (as dry), and the NBDi containing 0.1% by weight of the chlorine-substituted product was only 117.7 g.
(Purity conversion yield = 59.3%). The results are shown in Table 1.

Comparative Example 2 The procedure of Example 1 was repeated, except that the hydrochloric acid gas was charged from 0.5 hour before the simultaneous addition of the raw material NBDA and the solvent. NBDA hydrochloride has particles of 500 μm or less of 71.2
%Met. The filter cake weighed 18.3 g (as dry), and the NBDi containing 0.1% by weight of the chlorine substitution product was only 16
7.3 g (purity conversion yield = 84.6%) was obtained.

[0026]

[Table 1]

Comparative Example 3 A test was conducted in which the phosgenation reaction time of Comparative Example 1 was extended from 8 hours to 20 hours. NBDA hydrochloride is 500 μm
The following particles were 33.4%. 70.0g of filter cake
There is also (as dry), and NBDi containing a chlorine-substituted compound in an amount of 0.1% by weight is only 132.9 g (purity conversion yield =
Only 67.0%) was obtained. Even if the phosgenation time was extended, the amount of filter cake was not significantly improved, and the yield was only slightly increased.

Example 5 As in Example 1, m-xylylenediamine (hereinafter referred to as m-X
(Abbreviated as DA) 136.2 g (1.0 mol), 400 g of solvent amyl acetate in a solvent dropping device, and 800 g of remaining solvent amyl acetate in a reaction flask (m-XDA concentration = 1)
The same test as in Example 1 was carried out. m-XDA hydrochloride has particles of 500 μm or less.
It was 9.6%. The amount of the unreacted m-XDA hydrochloride as a filter cake was 1.5 g (as dry), and m-chloromethylbenzyl isocyanate (hereinafter abbreviated as m-CBi) was 0.4 g.
176.5 g of m-xylylene diisocyanate (hereinafter abbreviated as m-XDi) contained in weight% (purity conversion yield = 9)
3.0%) was obtained. The results are shown in Table 2.

Example 6 As in Example 5, the reaction flask was charged with the solvent amyl acetate 50.
0 g, and 136.2 g (1.0 mol) of m-XDA and 170 g of the remaining solvent were charged into the dropping device (m-XDA concentration =
20.3% by weight (relative to solvent), and the same test as in Example 5 was performed. The m-XDA hydrochloride had 98.4% of particles of 500 μm or less. The amount of unreacted m-XDA hydrochloride as a filter cake was 1.6 g (as dry), and m-CBi was 0.8.
174.5 g (yield in terms of purity = 92.1%) of m-XDi containing wt% was obtained. The results are shown in Table 2.

Example 7 As in Example 5, 700 g of the solvent amyl acetate was placed in a 3 l reaction flask, and 136.2 g (1.0 g) of m-XDA was added to the dropping device.
And 1300 g of amyl acetate as a solvent (m-X
The same test as in Example 5 was performed with DA concentration = 6.8 wt% (vs. solvent). The m-XDA hydrochloride had 99.8% of particles of 500 μm or less. The amount of unreacted m-XDA hydrochloride as a filter cake was 0.3 g (as dry), and m-CBi
Was obtained to obtain 179.2 g of m-XDi containing 0.4% by weight (purity conversion yield = 94.5%). The results are also shown in Table 2.

Example 8 A test was conducted in the same manner as in Example 7 except that 1200 g of amyl acetate as a solvent was charged in a reaction flask and m-XDA was directly added dropwise. In the m-XDA hydrochloride, 83.0% of particles were 500 μm or less. The amount of unreacted m-XDA hydrochloride as a filter cake was 2.8 g (as dry), and m-CBi
Was obtained to obtain 174.8 g of m-XDi containing 0.4% by weight (purity conversion yield = 92.3%). The results are shown in Table 2.

Comparative Example 4 1200 g of the solvent amyl acetate and m-XDA136.2
The test was performed in the same manner as in Example 5 except that (1.00 mol) was charged into the reaction flask from the beginning. The m-XDA hydrochloride had 75.7% of particles having a size of 500 μm or less. m
-M-XDi 173.3 containing 0.4% by weight of CBi
Although g (purity conversion yield = 91.7%) was obtained, the amount of unreacted m-XDA hydrochloride was as large as 11.5 g (as dry). The results are shown in Table 2.

[0033]

[Table 2]

Comparative Example 5 A test was conducted by extending the reaction time of Comparative Example 4 from 8 hours to 12 hours. The m-XDA hydrochloride had 69.8% of particles of 500 μm or less. The amount of unreacted m-XDA hydrochloride as a filter cake was as large as 9.6 g (as dry), and m-CBi
167.2 g of m-XDi containing 0.5% by weight (purity conversion yield = 88.2%) was obtained. Even if the phosgenation time was extended, the amount of filter cake was not significantly improved, and the yield was slightly decreased.

COMPARATIVE EXAMPLE 6 From 11.4% by weight of m-XDA, the same amount as 20.
The same test as in Comparative Example 4 was conducted by changing to 3% by weight.
As a result, the average particle size of m-XDA hydrochloride was 48.7% of particles having a particle size of 500 μm or less, and the amount of unreacted m-XDA hydrochloride filter cake was 16.9 g (as dry), which was very large. In addition, the obtained m-XDi amount is 0.4 for CBi.
168.5 g contained in weight% (purity conversion yield = 88.9)
%)Met.

Examples 9 to 12 The procedure of Example 5 was repeated except that the solvent was changed. The results are shown in Table 3.

[0037]

[Table 3]

Examples 13 to 14 and Comparative Examples 7 to 8 Example 1 and Comparative Example 7 except that the aliphatic amine was changed to hexamethylenediamine (abbreviated as HDA) and bisaminosimexhexylmethane (abbreviated as HMDA). The same procedure as in Comparative Example 1 was performed. The results are shown in Table 4.

[0039]

[Table 4]

[0040]

EFFECTS OF THE INVENTION According to the present invention, the objective aliphatic polyisocyanate can be easily and extremely stably produced with a high yield and a small amount of unreacted filter cake. Highly valuable to.

Claims (2)

[Claims] 1. An aliphatic polyamine and hydrochloric acid gas are simultaneously charged into an ester solvent to produce an aliphatic polyamine hydrochloride, and then reacted with phosgene.
Method for producing aliphatic polyisocyanate. 2. The method according to claim 1, wherein the aliphatic polyamine is selected from bis (aminomethyl) norbornene, xylylenediamine, bis (aminocyclohexyl) methane and hexamethylenediamine.