JPH02270854A - Novel diisocyanate and production thereof - Google Patents

Abstract

NEW MATERIAL:alpha-(3-Isocyanatophenyl)ethyl isocyanate expressed by formula I. USE:Usable as a raw material for polyurethane resins and polyurea resins in foams, elastomers, synthetic leathers, coatings, adhesives, films, etc. PREPARATION:alpha-(3-Aminophenyl)ethylamine expressed by formula II subjected to a cold heat two-stage phosgenation method for direct reaction thereof with phosgene to afford the compound expressed by formula I. Alternatively, the compound expressed by formula I is obtained using a method for phosgenating an amide hydrochloride by previously synthesizing a salt, such as hydrochloride, of the diamine expressed by formula II, suspending the resultant salt in an inert solvent and reacting the salt with phosgene.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a novel diisocyanate and a method for producing the same.

The isocyanate of the present invention is a diisocyanate with a novel structure, and can be used in a wide variety of applications, including as a raw material for polyurethane resins and polyurea resins, foams, elastic bodies, synthetic leathers, paints, adhesives, and films.

[Conventional technology]

Conventionally, as aromatic diisocyanates, toluylene diisocyanate (hereinafter abbreviated as TDI) and diphenylmethane diisocyanate have been industrially mass-produced and are used in a wide range of fields as raw materials for polyurethane resins and polyurea resins. Naphthalene diisocyanate, tolidine diisonanate, etc. are also used industrially.

Furthermore, as aliphatic diisocyanates, hexamethylene diisonanate and xylylene diisocyanate are industrially used as non-yellowing and non-yellowing types, respectively.

Alicyclic isocyanates include isophorone diisocyanate (hereinafter abbreviated as IPDI) and di(isocyanatocyclohexyl)methane (hereinafter abbreviated as H,2-MDI),
All of them are used industrially as non-yellowing diisocyanates.

Among these, IPDI has different characteristics in its reactivity with active hydrogen compounds such as polyols with the structure ni, isocyanana-IJ5.
Used in coating agents and other applications.

In addition, there are uses that utilize the difference in reactivity between the two isosoana-1 groups of T D l 4: is 2.4-T I) l with active hydrogen compounds.

[Problem to be solved by the invention]

The object of the present invention is to provide a novel diisocyanate-1 compound having a completely different structure that does not belong to any of the above-mentioned prior art.

[Means for Solving the Problems] The object of the present invention is to obtain α-(3-isosoanatophenyl)ethyl isocyanate (hereinafter referred to as l E B (abbreviated as l).

C1(.

NcOH The IEB I of the present invention is similar to the conventional Jison Anner 1-
Compared to other compounds, it has the following excellent characteristics.

That is, as shown in (1), IEBI has both an isocyanate group directly bonded to an aromatic ring and an isocyanate group bonded to an aliphatic carbon.

The reactivity of isocyanate groups directly bonded to aromatic rings with active hydrogen compounds is much greater than the reactivity of isocyanate groups bonded to aliphatic carbons with active hydrogen compounds. expected to be used for. For example, by first reacting an isocyanate group directly bonded to an aromatic ring with an active hydrogen compound, It is expected that useful prepolymers or i-1 adducts having the retardant or non-yellowing characteristic of isocyanates can be obtained.

In addition, since it has a substituent at the meta position of the aromatic ring, the urethane resin of the present invention (based on l E +31) can have appropriate mechanical strength, heat resistance, t resistance, and +V properties. Be expected. Moreover, it has been found that the synthesis of IEBI of the present invention can be carried out in a commercially advantageous method by reacting the diamine of formula (n) or its salt with phosgene by the method described below, and the present invention completed.

That is, the IEBI of the present invention can be obtained by directly reacting the diamine represented by Il with phosgene, or
It is produced by a method of synthesizing a salt such as a hydrochloride of a diamine represented by formula (Il), suspending it in an inert solvent, and reacting it with phosgene.

The previous book describes a method called "cold-thermal two-stage phosgenation," and although there are no particular limitations on the reaction method, the reaction for synthesizing IEBI can be carried out even if the reaction temperature of the second stage phosgenation is relatively low. By discovering that isocyaners of the desired quality can be obtained in high yields in a relatively short reaction time, the selection range of inert solvents used in the reaction is extremely wide, and the heat required to maintain the reaction temperature is The range of media selection has also expanded.

That is, phosgene gas is dissolved in an inert solvent at 0 to 20°C, preferably 0 to 5'C, and then, while introducing a predetermined amount of phosgene, the amount (n) of diamine dissolved in the inert solvent is added. During this time, the temperature of the reaction solution is kept below 20°C, and the generated hydrogen chloride and excess phosgene are discharged through a reflux condenser. After addition of the diamine solution, the reaction is continued for a predetermined time. Next, the reaction solution is heated, and the second
Raise the temperature to the stage reaction temperature. The second stage reaction temperature is 50-14
0'C1 is preferably 70 to 100'C, and after raising the temperature to a predetermined temperature, the reaction is continued for a predetermined time while continuing to introduce phosgene. The reaction is complete when the reaction solution slurry is completely dissolved. In this way, the objective can be achieved even when the second stage reaction temperature is lower than that of the conventional two-stage cold and hot phosgenation. In addition to chlorinated hydrocarbons such as dichlorhenzene, aromatic hydrocarbons such as xylene and toluene, esters such as ethyl acetate, butyl acetate, and amyl acetate, and low-boiling aromatic carbons such as benzene. Even with hydrogen, the phosgenation reaction can be completed without the need to carry out the reaction under particular pressure. This makes it possible to select inert solvents within a wide range, and at the same time, if an inert solvent with a low boiling point is selected, it is possible to perform desolvation after the phosgenation reaction extremely easily. It is.

The latter method is called "amine hydrochloride phosgenation method", and the diamine hydrochloride of the above formula (II) is synthesized in advance. The hydrochloride salt can be easily synthesized by treating the diamine of formula (1) with hydrogen chloride or concentrated hydrochloric acid in a well-known manner. In this case, as the solvent for the phosgenation reaction, a wide range of inert solvents can be selected as mentioned above, so if a solvent with a relatively high solubility of hydrogen chloride is used in the production of diamine hydrochloride, the diamine will be relatively clean. can be completely converted into hydrochloride. In the phosgenation of hydrochloride, the hydrochloride is dispersed as much as possible in an inert solvent by strong stirring in the reactor, and the reaction temperature is maintained at 70-16°C.
The temperature is maintained at 0°C, preferably 90 to 120°C, and phosgene is introduced. The progress of the reaction can be estimated from the amount of hydrogen chloride gas generated and the disappearance of diamine hydrochloride insoluble in the inert solvent, and the fact that the reaction solution becomes clear and homogeneous. The hydrogen chloride and excess phosgene gas generated are discharged through a reflux condenser.

In both cold and hot 2-phosgenation methods and phosgenation of amine hydrochloride, after the reaction is complete, nitrogen gas is introduced into the reaction solvent, the dissolved phosgene is removed, and the mixture is cooled and filtered. , the inert solvent is distilled off under reduced pressure, and the diisocyanate produced is purified by distillation under reduced pressure or the like to obtain the desired diisocyanate (1).

〔Example〕

The present invention will be specifically explained below using Examples.

Example 1 Using α-(3-aminophenyl)ethylamine represented by formula (It) as a raw material, phosgenation was carried out by a cold and hot two-stage method. 800 g of ortho-dichlorohenzene was charged into a 21 reaction flask equipped with a stirrer, a thermometer, a phosgene gas introduction tube, a cooling tube, and a dropping funnel, and after stirring, the reaction flask was placed in an ice water bath to maintain the internal temperature at approximately 2°C. , 75 phosgene gas
g/h into the flask for 1 hour. Next, 40 g (0,294 mol) of the above diamine (II) dissolved in 307 g of ortho-dichlorohenzene was added dropwise over 1 hour. When dropping amine, add 75% phosgene gas.
Cold phosgenation was carried out at 2-7 °C while introducing at a rate of 508 g / h, and after the dropwise addition phosgene was introduced at a rate of 508 / h into the fire at 7-16 °C for 30 minutes. After dropping the amine, the inside of the flask became a pale yellowish white slurry liquid.

Next, while introducing phosgene at a rate of 50 g/h, the temperature of the reaction flask was raised to 74°C over 2.5 hours.

While continuing to introduce phosgene into the flame after raising the temperature, the reaction temperature was increased to 74.
Thermal phosgenation was carried out at ~100°C for 2 hours. During the thermal phosgenation process, the liquid in the flask became a light brown transparent solution.

A total of 210 g of phosgene gas was introduced through cold and hot two-stage phosgenation. This was about 3.6 times the theoretical amount. After the thermal phosgenation was completed, nitrogen gas was introduced at 90°C for 2 hours to perform degassing. After cooling and filtration, the solvent, orthodichlorohenzene, was distilled off under reduced pressure to obtain about 55 g of a brown reaction liquid. Further, by vacuum distillation, a small amount of α-(3-
By removing isocyanatophenyl)ethyl chloride, the boiling point of approximately 44.7 g 136 °C/10 mm
11 g of fraction was obtained (colorless transparent liquid, NC0% 44.6
1). The elemental analysis values of this fraction were as follows.

Elemental analysis value (%) (as C1o11nNzOz) CHN Calculated value 63.76 4.25 14.88
Analysis value 63.86 4.22 14.91
In addition, the IR spectrum shown in Figure 1, 'H-N in Figure 2
An MR spectrum was obtained. Furthermore, in the GC-MS spectrum, (M") -188 was observed, which coincided with the molecular weight of the compound represented by formula (1), 188.2. From the above, this fraction has the target product α-(3- It was identified as isocyanatophenyl)ethylisona-1.

Example 2 Phosgenation was performed using the diamine represented by 2 (jl) as a raw material by the hydrochloride method. Ol-1-dichlorohenzene was used as a solvent. A reaction flask similar to that in Example 1 was prepared with formula (1
54.3 g (0.4 mol) of cyamine shown in 1) was added to 1
．． Pour 7 mL of solution into 555 g of ol-1-dichlorohenzene, raise the temperature to 145-167 "C; E while stirring, and then add nitrogen gas at a rate of 300 mj!/min], 5
The water in the system was removed by bubbling the solution for a period of time to aerate the solution. Then, after the solution was cooled to a temperature of 19° C., hydrogen chloride was bubbled through the solution while stirring to generate hydrochloride. As the hydrochloride was formed, the temperature of the liquid rose, but it was cooled and maintained below 35°C. After 15 hours, the introduction of hydrogen chloride was stopped, and the resulting hydrochloride slurry was heated to 120'C over 2 hours while blowing phosgene gas at a rate of 50 g/h. 1 more
7I Kusugen injection was continued for 2 hours at 20'c. Since the reaction solution became almost clear, the phosgene injection was stopped and 1
Degassing was performed by blowing nitrogen gas at a rate of 300 mff/min at 20°C for 2 hours. The total amount of phosgene introduced is 200
It was g.

This is about 2.5 times the theoretical amount. After the degassed reaction liquid was cooled and filtered, the solvent ol-1-dichlorohenzene was distilled off under reduced pressure to obtain about 65 g of a one-color reaction liquid. Further, by-product α-(3-isocyanophenyl)ethyl chloride was removed by distillation under reduced pressure to obtain about 46.4 g of -1: fraction. The second fraction was a colorless and transparent liquid with an NC of 0% and 44.60. The elemental analysis values were as follows.

Elemental analysis value (%) (as C+oLIIzOz) Cl-(N Total 34 [I direct 63.76 4.25
14.88 Analysis value 63.51. 4゜08
14.7811'? Spectrum, lH-NM
The same R spectrum as in Example 1 was also obtained.

Example 3 Normal butyl acetate was used as a solvent for phosgenation. 2P same as Example 1, 1000g of n-butyl acetate was charged into the reaction flask, and after stirring, the reaction flask was placed in an ice water bath, the internal temperature was maintained at 3-5'C, and the tosogen gas tloOg was added.
/h into the flask for 1 hour. Next, the diamine (n
) 3 g (0.40 mol) of 5C was added dropwise over 1 hour. When dropping the amine, cold posgenization was performed at 5 to 10°C while introducing phosgene gas at a rate of 75 g/h.
Add 75g of phosgene for 30 minutes at 5-8°C.
/h.

After dropping the amine, the inside of the flask is a white slurry liquid.
became. Then phosgene was added at a rate of 12.5 g/h 1'
While introducing the reaction, the liquid in the flask was heated to 80' for 30 minutes.
Warmed to 4 degrees C. After increasing/'M, phosgene was introduced at a rate of 75 g/h and the reaction temperature was 80 ± 2゛ for 1 hour at 9
[] -+l 2° (:) Thermal phosgenation was carried out for 2 hours. During the thermal phosgenation process, the liquid in the flask turned pale yellow and transparent.
Don't touch the liquid. A total of 22.5 g of phosgene was introduced by cold and hot two-stage phosgenation. This was about 28 times the theoretical amount. After the completion of thermal phosgenation, nitrogen gas was added at 85±2"C for about 2
The gas was introduced at a rate of 50 d/min for 2 hours to perform degassing. After cooling, the mixture was filtered, and the solvent n-butyl acetate was distilled off under reduced pressure to obtain about 75 g of a brown reaction liquid.

It was further purified by vacuum distillation to obtain about 56.2 g of main fraction. This 1-distillate is a colorless transparent liquid with N00%44.5
The elemental analysis, IR spectrum, gas chromatography, and 'HNMR spectrum were the same as in Example 1.

The diamine represented by the formula (n) as a raw material was synthesized by the method described in Reference Example below.

(Reference example) 33.0 g of m-nitroacetophenone (
0.2 mol), 200 mff of methanol, and 4.6 g of nitric acid) were added, and the mixture was purged with nitrogen and stirred for a while.

Approximately 40 g of ammonia was introduced into the autoclave while cooling it with ice water. Continue to increase the hydrogen by l1 and make it 40k.
After setting the temperature to g/c-G, the temperature was raised to 70'Cε5-. React for 55 minutes at a temperature of E, and add 16.5 Nf of hydrogen!
The reaction was terminated because the absorption stopped at the point where it was absorbed.

After cooling to room temperature, the reaction solution was taken out and filtered, and the filtrate was vacuum distilled at a pressure of 5 to 6 mm) Ig to a distillate temperature of 1.
23.9g of fraction from 20 to 122°C (Yield 88.0%
) was obtained.

This liquid is colorless and transparent, and when the analysis values of elemental analysis, GC-MS spectrum, IR-spectrum, and 'H-NMR spectrum were investigated, the following data were obtained, indicating that α-(3-aminophenyl) It was identified as ethylamine.

Purity by gas chromatography was 99.3%.

(1) 'l(-NMR spectrum (100MHz
,,DMSO-66) δppm: 1.0-1.5 Ni CH3 proton 3H4,2
~5.3: -C-N11□ 211
6.1-7.2: Hensen ring proton 411(2) IR
Spectrum (rock salt plate, liquid film method) wave number cm-': 3
400.3340.3190.2940.1600.1
485.1455.1360.1310.1160 (3
) GC-MS spectrum El-MS spectrum: (M”) = 136 (Note,
Molecular weight of APEA Ce1l+□N2=136.2)(4
) Elemental analysis value (CIIH, □N2) CHN Calculated value (χ) 70.48 B, 81 20.
56 Actual value (χ) 70.45 8.91 20.3
8

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are diagrams showing an infrared absorption spectrum and an 'H-NMR spectrum of α-(3-isocyanatophenyl)ethyl isocyanate, respectively. Patent Applicant Mitsui Toatsu Chemical Co., Ltd. Procedural Amendment (Kite) August 10, 1999 Commissioner of the Japan Patent Office Yoshi 1) Moon Takeshi 1, Indication of the case 1999 Patent Application No. 90676 2, New title of the invention Diisocyanate 1 and its manufacturing method 3, and its relationship to the case of the person making the amendment Patent applicant address 3-2-5 Kasumigaseki, Choyoda-ku, Tokyo 4 Amendment order 1 Old = 1 (Delivery 8) July 1999 Month 2511 5, drawings subject to amendment

Claims (1)

[Claims] 1) α-(3-isocyanatophenyl)ethyl isocyanate represented by formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) 2) α-(3-aminophenyl) represented by formula (II)
A method for producing α-(3-isocyanatophenyl)ethyl isocyanate, which comprises reacting ethylamine or a salt thereof with phosgene. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II)