JPS60188356A - Preparation of lysine ester triisocyanate - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a coating compound without causing a colored component in high purity in high yield, by suspending and dispersing a lysine monoalkyl ester trihydrochloride in a nonaqueous organic solvent, washing it, redispersing it in the solvent, reacting it with phosgene. CONSTITUTION:A lysine monoalkyl ester trihydrochloride shown by the formula I (R is 2-5C alkyl) is reacted with phosgene to give lysine ester triisocyanate shown by the formula II. In the reaction, the compound shown by the formula I is suspended and dispersed into a nonaqueous organic solvent (e.g., benzene, O-dichlorobenzene, trichloroethane, etc.), filtered, separated, and the filtered cake is washed, the prepared filtered cake is similarly redispersed into the organic solvent to give a suspension, which is reacted with phosgene. The dispersion and preparation is carried out in such a way that the filtered cake provides uniformly crystal of the compound shown by the formula I having preferably >=200mu average particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an aliphatic triisocyanate having the formula % (() [wherein R is an alkyl group having 2 to 5 carbon atoms] lysine ester triisocyanate, From the compound of formula (I), C11-1-H2N-(C1(2)4-CI-Nl-
12·l-lCl■C-0-R-NI(2·I(C6(D++) This invention relates to a method for obtaining a high-yield product with a low content of by-product acids such as coloring components.

Lysine ester triisocyanate (hereinafter abbreviated as LTl) is odorless at room temperature and is a compound useful in non-yellowing paints and l-, as disclosed in JP-A-53-135931.

The publication also describes a method for obtaining the corresponding LTi by phosgenating lysine monoalkyl ester trihydrochloride (hereinafter abbreviated as LA E'f').

According to the publication, LA ET, which is a raw material, is treated in the presence of an acid such as hydrogen chloride or P-toluenesulfonic acid.
There is a description that it can be produced by reacting lysine with an alkanolamine in an inert liquid reaction medium and separating the resulting water by azeotroping with the reaction medium. Further, a method is disclosed in which the crude LAE'T' thus obtained is recrystallized with alcohol and subjected to a phosgenation reaction.

However, as in the publication, the purified L obtained by recrystallization
Even in AET, it is unavoidable that water and alcohol derived from the crystallization solvent are mixed into the crystallized solids, albeit in small amounts.

However, in the production of isocyanates by phosgenation using LAET, even a small amount of water can cause the formation of colored impurities and tar.If you try to dehydrate and remove the solvent by drying the cake, even at low temperatures. Even during drying, the crystals melt and form a hard cake with large clumps with a particle size of 200 μm or more. It is difficult to atomize this cake because it easily melts, and even if the atomized cake is phosgenated, not only will the phosgenation reaction time be longer, but the quality of the LTi obtained will also be improved. Deteriorate.

Furthermore, since LAET is highly hygroscopic, θ) to prevent moisture absorption becomes a major problem during pulverization.

As a result of intensive study on these points, the present inventors determined that the formula (
■) In the method of removing water and alcohol contained in LAET wet cake,
It has been found that the crystal grain size of the cake can be easily removed to a moisture content of at least 1% or less while maintaining the average particle size of 200μ or less without using drying means, and when LAET purified by the method of the present invention is used, The present invention has been achieved by being able to obtain LTi of good quality in a short phosgenation reaction time.

That is, the present invention provides a method for obtaining lysine ester triisocyanate of formula (TI) compound by subjecting lysine monoalkyl ester trihydrochloride of formula m compound to a phosgenation reaction. After suspension and dispersion in a solvent, the P lumps are separated by filtration and washed, and the obtained P lumps are again dispersed in a non-aqueous organic solvent to obtain an average particle size of preferably lysine monoalkyl ester trihydrochloride crystals. This is a method for producing lysine ester triisocyanate, characterized in that a suspension uniformly adjusted to have a diameter of 200 μm or less is used in a phosgenation reaction.

In the present invention, the lysine monoalkyl ester trihydrochloride of the above general formula (I) is prepared from the above-mentioned JP-A-53-]3593.
] It can be obtained based on the method described in the publication. That is, by introducing hydrogen chloride gas in a reaction medium such as a chlorinated aromatic hydrocarbon, lysine is reacted with ethanolamine, 2-amino-2-propanol, 2-
By reacting alkanolamines having 2 to 5 carbon atoms such as amino-1-propatol, 3-amino-1°C-furonol, 2-amino-1-butanol, and 5-amino-1-pentanol. If necessary, the corresponding compound of formula (I) can be obtained, which may be used after recrystallization if necessary.

Furthermore, the non-aqueous organic solvent used in the present invention is LAET.
It is preferable to use the solvent used in the isocyanation reaction with phosgene as it is, such as aromatic hydrocarbons such as benzene and toluene, chlorinated aromatic hydrocarbons such as 0-dichlorobenzene, or chlorinated fats such as trichloroethane. Examples include group hydrocarbons.

Advantageously, LAET is soluble in polar solvents such as water or methanol, but is poorly soluble in other solvents such as those mentioned above, so that little loss occurs during filtration and washing. Furthermore, although such a solvent is normally used which is incompatible with water, it was unexpected that water in the furnace mass could be almost completely removed by simple filtration and washing.

In the present invention, in the step of suspending and dispersing LAET in a non-aqueous organic solvent, the organic solvent is usually 1. , used in a range of 4 to 10 times that of AET. Further, it is preferable to use a dispersion device such as a LAET homomixer or a colloid mill, and the dehydration effect is further improved by dispersing the water enclosed in the crystals.

1, AET distributed in this way is usually 2
The particles have a particle size of 00 μm or less and are suspended in an organic solvent, which is then passed through for solid-liquid separation.

As the filtration method, any filtration method commonly used in the production of chemical products, such as reduced pressure, pressurization, or centrifugal filtration, can be applied.

Next, the solid-liquid separated mud mass is washed, preferably using the same non-aqueous organic solvent used in the dispersion step, in order to remove water adhering to the surface.

In the method of the present invention, since the drying step is omitted, the washing of the door blocks cannot be omitted, but the number of times of washing and the amount used are changed as appropriate depending on the water content of LAET. One or two washes are usually sufficient. It goes without saying that the waste solvent after washing can be reused by separating and dehydrating it together with the solid-liquid separated tear fluid.

The LAET cake purified in this way contains some lumps by filtration, so the crystals of the lumps are completely loosened and made into a fine suspension state with a particle size of 200μ or less, which is then processed for phosgenation. For processing, it is redispersed in a non-aqueous organic solvent adjusted to the concentration of the phosgenation reaction. Further, as the non-aqueous organic solvent, it is preferable to use the same type of solvent as the solvent used in the phosgenation reaction. The phosgenation reaction is usually O-
The reaction is carried out in a chlorinated, aromatic hydrocarbon solvent such as dichlorobenzene, and it is desirable to use a chlorinated aromatic hydrocarbon for dispersion.

In addition, when dispersing, the coarse 1. Similar to the AET dehydration and dispersion process, it is preferable to carry out using equipment with dispersion ability such as a homomixer, colloid mill, or volator pump. It is preferable to uniformly disperse it in a suspension whose concentration is adjusted so that it can be used for production.

The LAET suspension prepared by the above method is then subjected to a phosgenation step.

The phosgenation reaction is carried out at 80 to 1.50°C, preferably at 1.
Perform at 20°C to 150°C. The obtained reaction mass is degassed, the solvent is removed so that the solvent content is 1% or less, and then distilled to obtain LTi in high yield.

The LTi obtained by the method of the present invention is a highly purified product containing few coloring components and is suitable for paints.

Example 1 Lysine-β-aminoethyl ester tribasic hydrochloride hydrochloric acid bulk (solid content 80% methanol 10%, water 10%) 1.11
．． 1'7 was mixed with O-dichlorobenzene 6 ('in!7), treated with a homomixer at 20 Orpm for 20 minutes, and the resulting block was filtered with O-dichlorobenzene 60
After washing with 0Q, 200 ml of 8-grade Mito mass with a water content of 180 ppm was obtained. (Methanol was not detected.) 60 0-dichlorobenzene (ODCB) was added to this dehydrated P mass.
0q was added and slurried using a homomixer. The average particle size of the lysine-β-aminoethyl ester tribasic hydrochloride in the resulting suspension was 20 to 40 μm.

This suspension was transferred to a four-eye flask, and phosgene was blown into the flask at a flow rate of 3 mol/'amine/' hour at 140°C for 10 hours to carry out a phosgenation reaction. After completion of phosgenation,
Nitrogen gas was blown in at 10 IJ/Hr for 2 hours to degas. After distilling 0DCB, 0.5mx1-(9 in 1
A distillate fraction of 80°-220°C was obtained with a yield of 90%. The purity of distilled lysine diisocyanate-β-isocyanate ethyl ester is 99%, and the hue (A, PHA) is 18
It was 0.

Water-containing raw mass of thyl ester trihydrochloride (LAET solid content 80
%, methanol 10%, water 10%) at 1100C;
After vacuum drying for an hour, the resulting dry cake was ground in a colloid mill. During pulverization, fusion of crystals occurred between the grinders, making it difficult to reduce the particle size to 200 or less. Lysine β-aminoethyl ester tribasic hydrochloride 0-dichlorobenzene having an average particle size of 250 μm was added to form a 10% slurry. This was phosgenated and post-treated under the same conditions as in Example 1, but the yield of the desired product was 60%, and its hue (APHA) was 500 or more and pale yellow.

Example 2 600 g of chlorobenzene was added to 200 g of lysine-key aminoisopropyl ester trihydrochloride (50% solids, 10% methanol, 25% n-proyl alcohol, 15% water).
g was added thereto, and fine dispersion treatment was performed using a colloid mill. After filtering, it was washed with 100 g of chlorobenzene to obtain a dehydrated lump. The water content in the mud mass was 300 ppm (Karl Fischer method), and the alcohol content was 120 ppm (gas chromatography). 10% to this dehydrated raw mass
Monochlorobenzene was added to the slurry to give a slurry concentration of , and the mixture was reslurried using a homomixer. The average particle size of the particles was 30-50μ. The resulting slurry was phosgenated at a reaction temperature of 130° for 30 hours in stream 1 of 3 moles/amine/h, followed by degassing and desolvation.
], :H1'2-1 [1°/'0, 081m1-1
') to obtain lysine diisocyanate-isocyanato isopropyl ester in a yield of 70%. Its purity was 99%, and its hue (APHA) was 200.

Comparative Example 2 The exact same hydrochloride-containing raw mass used in Example 2 was mixed with 10
After vacuum drying at 0°C for 5 hours, the resulting dry cake was pulverized using a sand grinder. Similar to Comparative Example 1, crystal fusion occurred on the bead surface, making it difficult to atomize the beads.
[average particle size], considerable loss occurred in reducing the average particle size to n Oμ.

Monochlorobenzene was added to this fine grain, and the yield of 10-isocylinate isopropyl ester was 45%, the purity was 98%, and the hue (APHA) was 11- or more than 500.

patent applicant Mitsui Toatsu Chemical Co., Ltd. 12-

Claims (2)

[Claims] (1) General formula (■) CII-1・I-1,, N-(CI-12)4-CI-
Lysine monoalkyl represented by 1-NI-1,, .T-rclac-o-r 12.lIC1(■) 1 [wherein R is an alkyl group having 2 to 5 carbon atoms] Using ester trihydrochloride,
This is subjected to a phosgenation reaction to form 2) OCN-(CH2)
4-CI-NCO α-R,NCO(TI) 1 [wherein, R is the same as R in D] In the method for obtaining lysine ester triisocyanate, lysine monoalkyl ester trihydrochloride After being suspended and dispersed in a non-aqueous organic solvent, the obtained furnace mass is separated by filtration and washed, and the obtained furnace mass is dispersed again in a non-aqueous organic solvent.The resulting suspension is used for the phosgenation reaction. A method for producing lysine ester triisocyanate, characterized by: (2) The method according to claim 1, wherein the non-aqueous organic solvent is the same type of solvent as the solvent used in the phosgenation reaction.