KR20200065977A - Method of preparing polyaspartic ester - Google Patents

Abstract

The present invention relates to a method for preparing a catalyst for a reductive amination reaction, a catalyst for a reductive amination reaction produced thereby, and a method for preparing a polyaspartic ester in high yield from a polyetheramine compound with high amine value prepared using the same.

Description

Manufacturing method of polyaspartic ester {METHOD OF PREPARING POLYASPARTIC ESTER}

The present invention relates to a method for producing polyaspartic esters.

Polyaspartic esters are mainly used for high-quality polyurea coatings for automotive and architectural applications, and can be prepared through the Michael addition reaction of dialkyl maleates with aromatic and aliphatic amines. Aliphatic amines are polyaspartic based on aromatic amines. It reacts with isocyanate faster than esters and has a low viscosity, making it widely used commercially.

In order to prepare a polyaspartic ester, it is preferable that polyether amine (PEA) used as a raw material has a total amine value (%) of 97% or more. When the amine value is less than 97%, unreacted materials (polypropylene glycol) are eluted, and thus, the coating film of the final product is unstable and hardly cured. In the case of Korean Patent Application No. 2012-0108179, when a PEA-producing powder-type catalyst is introduced in a commercial process, this reaction is a liquid-high-pressure reaction, and it is difficult to continuously produce products. In order to separate the catalyst in powder form, a catalyst recovery/filtration/washing step is applied as an additional process, and thus has a disadvantage of low economic efficiency. In addition, since the catalyst in the form of powder is produced by a precipitation method, the manufacturing process is much more complicated than when the catalyst is prepared by an impregnation method. Korean Patent Application No. 2011-0021513 relates to the synthesis of mono-isopropyl amine (MIPA) from isopropyl alcohol (IPA), but the desired product (MIPA) yield is less than 80%. It has the disadvantage of being very low.

In addition, the conventional polyetheramine-based polyaspartic ester was prepared by adding a dialkyl malate in the presence of a basic catalyst and polyetheramine in a nitrogen atmosphere based on a reflux device, followed by stirring at 80°C for about 20 hours to react. According to Publication No. 103524700A, it takes 15 hours at 90°C, 13 hours at 100°C, and 2 hours at 180°C to 220°C. The final mixture is stored for about a month at room temperature so that the Michael addition reaction takes place sufficiently, and the final material is yellow in a transparent liquid. The heating method using the reflux device is a method in which the moisture in the object to be heated is transferred from the surface of the object to be heated by heat conduction or convection by heat radiation. This heating method is very slow and inefficient in terms of energy transfer because it is affected by the thermal conductivity of various materials to be permeated. In addition, the temperature of the sample container becomes higher than the temperature of the mixture until the mixture reaches thermal equilibrium, and the heat of conduction makes operation and control of the reaction difficult. Since the heat from the external heat source has to be transferred from the surface of the heat source through conduction and convection, it takes a lot of time until the target material is evenly heated. In addition, even if the stirring efficiency is good, a phenomenon in which the degree of heating is different for each zone may occur according to a distance from a heat source, which may cause a non-uniform reaction. In addition, in order to reduce the reaction time, when the temperature is 100°C or more, there is a problem of separation of side reactants generated according to the bond between dialkyl maleates. In addition, there is a problem that it takes an additional reaction time more than a month to completely react.

Accordingly, the present inventors have simplified the method for preparing the catalyst and prepared a polyetheramine compound having a high amine value using a new catalyst to which a carrier having a form that can be easily used repeatedly is obtained, and then obtained a polyaspartic ester in high yield in a short time. The manufacturing method was developed.

Korean Patent Application No. 2012-0108179 Korean Patent Application No. 2011-0021513 Chinese Patent Application Publication No. 103524700A

The present invention provides a method for producing polyaspartic ester (PAE) in high yield from polyetheramines prepared at high amine values using a catalyst for a reductive amination reaction.

The present invention, (1) in the presence of a catalyst for a reductive amination reaction and hydrogen, contacting polypropylene glycol (PPG) with an amine compound to produce a polyetheramine; And (2) heating the polyetheramine produced in step (1) by mixing it with di(C _1-6 alkyl) maleate in the presence of a basic catalyst, and reacting it with heat. It provides a method for producing a polyaspartic ester (PAE) in which the time for the yield of the polyaspartic ester (PAE) to reach 99.5% or more is 5 to 60 minutes.

The present invention simplifies the method for preparing the catalyst and utilizes a new catalyst to which a carrier (eg, spherical) having a form that can be easily used repeatedly is used, and a amine value of 99% or more from the reductive amination reaction of polypropylene glycol (PPG) By preparing polyether amine (PEA) having (Amine Value), unreacted PPG was eluted to prevent the unstable coating and curing of the final product. In addition, polyetheramine-based polyaspartic esters can be obtained with a high yield of 99.5% or more within 1 hour.

1 is a result of TPR (temperature-programmed reduction) analysis in a hydrogen atmosphere to confirm the reduction temperature of the prepared catalyst.
2 is an XRD analysis result of the prepared catalyst.

The present invention provides a method for producing a polyaspartic ester (PAE) in high yield from polyetheramines prepared at a high amine value using a catalyst for a reductive amination reaction.

According to one embodiment according to the invention,

(1) in the presence of a catalyst for a reductive amination reaction and hydrogen, contacting polypropylene glycol (PPG) with an amine compound to produce polyetheramine (PEA); And

(2) mixing the polyetheramine produced in step (1) with a di(C _1-6 alkyl) maleate in the presence of a basic catalyst to heat react, and polyaspara to polyetheramine input weight. A method for producing a polyaspartic ester is provided, wherein the time for the yield of the polyaspartic ester (PAE) to reach 99.5% or more is 5 to 60 minutes.

In order to produce polyaspartic esters in high yield, the polyetheramine used as a raw material must have an amine value of at least 97% or more. When the amine value is less than 97%, unreacted PPG is eluted, resulting in unstable coating of the final product and hardening. In order to achieve the above object, the catalyst for a reductive amination reaction according to an embodiment of the present invention may be a metal supported catalyst comprising a cobalt compound, a yttrium compound and a palladium compound fixed to a carrier.

According to one embodiment according to the present invention, the catalyst for the reductive amination reaction is a cobalt (Co) compound, a yttrium (Y) compound and a palladium (Pd) compound of 180 to 250m ² / g specific surface area and 330 to 400m ² It is a catalyst supported on a spherical γ-Al ₂ O ₃ carrier having a meso-pore surface area of /g.

In one embodiment of the present invention, the carrier may be selected from the group consisting of SiO ₂ , θ-Al ₂ O ₃ , γ-Al ₂ O ₃ and SiO ₂ -Al ₂ O ₃ , for example 500-600 It may be γ-Al ₂ O ₃ heat-treated at 5°C for 5-7 hours, or at 600°C for 6 hours, or at 600-700°C for 4-6 hours.

In one embodiment of the present invention, the carrier may be γ-Al ₂ O ₃ having a specific surface area and an acid point of 180 to 250 m ² /g.

In one embodiment of the present invention, the carrier may be γ-Al ₂ O ₃ having a distribution of meso-pore of 55% or more relative to the total carrier pore volume, and/or spherical, cylindrical, or square (cube Form) of γ-Al ₂ O ₃ .

In one embodiment of the present invention, the metals are precursors, for example, Cobalt(II) nitrate hexahydrate, Cobalt(II) chloride hexahydrate, Cobalt(II) acetate tetrahydrate, Yttrium nitrate hexahydrate, Yttrium(III) chloride hexahydrate, Palladium( II) nitrate dihydrate, Palladium(II) acetate, Palladium(II) chloride, Palladium(II) Bis(trifluoromethansulfonate) can be used.

In one embodiment of the present invention, in a catalyst for a reductive amination reaction comprising a cobalt compound, a yttrium compound and a palladium compound as an active ingredient, the cobalt metal is contained in an amount of 1 to 12% by weight based on the weight of the carrier, and yttrium The metal is contained in an amount of 0.05 to 30% by weight based on the weight of the cobalt metal, and the palladium metal may be contained in an amount of 0.01 to 50% by weight based on the weight of the cobalt metal.

The method of supporting the above-described active ingredient on the carrier as described above is a method of directly supporting the active ingredient on a dehydrated carrier, or a method of mixing the active ingredient and the carrier to support it by sedimentation, followed by firing. Conventional loading methods known in the industry can be applied.

At this time, the content of the active ingredient supported on the carrier may be determined in consideration of a range over which the minimum activity can be expressed and the effect of reducing the amount of the active ingredient used according to the introduction of the carrier, and is not particularly limited. However, preferably, the active ingredient may be included in 1 part by weight or more, or 1 to 200 parts by weight, or 10 to 150 parts by weight based on 100 parts by weight of the carrier. Here, when the active ingredient is included in 100 parts by weight based on 100 parts by weight of the carrier, it can be expressed as'the active ingredient is supported at 50% by weight'.

In addition, the catalyst may further include a cocatalyst compound that can further improve the activity of the above-described active ingredient. The co-catalyst compound may be carried together on the above-described carrier, and conventional co-catalyst compounds known in the art may be employed without particular limitation.

The catalyst prepared according to the present invention can significantly lower the reduction temperature of the catalyst, thereby removing the deactivation factor of the catalyst, thereby maintaining the life of the catalyst for a long time. To confirm this, the present inventors used a catalyst carrier at 600°C for 6 hours Heat-treated spherical γ-Al ₂ O ₃ is used, and each metal is a precursor to each of Cobalt(II) nitrate hexahydrate (Purity, 98%), Yttrium nitrate hexahydrate (Purity, 99.999%), and Palladium(II) nitrate dihydrate (Purity). , 14.47%). At this time, each of the metals was prepared by measuring the weight based on the Cobalt precursor weight ratio of 100, Yttrium is 1 part by weight, Palladium is 0 parts by weight, 0.1 parts by weight, and 0.2 parts by weight of the electrolyte solution, impregnated into the alumina carrier (Incipient wetness impregnation). The results of analyzing each catalyst with a temperature-programmed reduction (TPR) in a hydrogen atmosphere to confirm the reduction temperature of the prepared catalyst are shown in FIG. 1. As shown in FIG. 1, by adding a palladium compound to a binary catalyst consisting of a cobalt compound and a yttrium compound (Pd(X 1) in FIG. 1 is 0.2 parts by weight of Pd based on 100 weight ratio of Cobalt precursor, Pd(X 1/2 ) Is 0.1 parts by weight of Pd based on the weight ratio of Cobalt precursor, Pd(X 0) means that Pd is not introduced). It was confirmed that the reduction temperature of high temperature of 515.9°C or higher can be reduced by half to 258.8°C. In addition, as shown in FIG. 2, it was confirmed through the X-ray diffraction analysis of the catalyst that Co ₃ O ₄ was mostly reduced by palladium even at a reduction temperature of 220° C. and existed as a cobalt metal.

The catalyst according to the present invention may be used for the production of polyetheramine (PEA) through reductive amination of polypropylene glycol (PPG).

On the other hand, according to another embodiment of the present invention, in the step (1), the amine compound may be a conventional compound containing an amine group without particular limitation, and preferably a primary amine compound or a secondary amine compound may be used. Can be. More preferably, the amine compound is ammonia, methylamine, ethylamine, propylamine, butylamine, ethylenediamine, aniline, piperazine, aminoethylpiperazine, diethylenetriamine, triethylenetetraamine, tetraethylenepentaamine , Pentaethylenehexaamine, diethylamine, dipropylamine, dibutylamine, isopropylamine, diisopropylamine, diisopropanolamine, ethanolamine, diethanolamine, and diisobutyleneamine It may be one or more compounds.

In step (1), in the step of contacting the polypropylene glycol with an amine compound, the weight ratio of the reactants is not particularly limited as it can be determined in consideration of reaction efficiency and the like within a range in which a series of reactions can be sufficiently performed. However, according to the present invention, the step comprises a molar ratio of polypropylene glycol to amine compound 1:5 to 1:30, or 1:10 to 1:20, and/or a molar ratio of polypropylene glycol to hydrogen 1:0.1. It may be advantageous in that it is performed at 1:5 to improve the reaction efficiency.

In step (1), the molecular weight (Mw) of the polypropylene glycol may be 200 to 4000.

And, the step (1) is at a temperature of 20 ℃ to 350 ℃ and a pressure of 1 bar to 300 bar, or at a temperature of 20 ℃ to 300 ℃ and a pressure of 1 bar to 250 bar, or 20 ℃ to 250 ℃ It can be advantageous in terms of improvement of reaction efficiency to be performed under temperature and pressure of 1 bar to 220 bar.

According to one embodiment according to the present invention, the polyetheramine produced in step (1) may have an amine value of 99% or more.

In one embodiment according to the present invention, the batch reactor may be used in step (1), and a catalyst filling space may be secured by using, for example, a basket made of SUS material to prevent catalyst loss due to agitation. At this time, a certain amount of the catalyst is charged into the basket, and ammonia is added in a ratio of 5 to 30 moles, and hydrogen is added in a ratio of 0.1 to 5 moles compared to the raw material (PPG) to perform the reaction under a high pressure condition of 100 bar or more.

Meanwhile, the step (2) may be exemplified by the following scheme 1.

[Scheme 1]

In one embodiment according to the present invention, the heating reaction in step (2) may be performed while irradiating the microwave, and the frequency of the microwave may be 1.0 to 10 GHz or 2.0 to 8.0 GHz.

In one embodiment according to the present invention, the heating reaction in step (2) may be performed at 30 to 120°C for 3 to 70 minutes, or at 40 to 100°C for 5 to 60 minutes.

The basic catalyst of step (2) is pyridine, sodium hydroxide (NaOH), barium hydroxide (Ba(OH) ₂ ), sodium ethoxide, piperidine, 2,4,6 -Tri(dimethylamiomethyl)phenol (2,4,6-tris(dimethylaminomethyl)phenol, triphenylphosphine) may be one or more selected from the group consisting of.

In one embodiment according to the present invention, the basic catalyst of step (2) may be present in an amount of 0.1% or less based on the total weight of the polyetheramine. In one embodiment according to the present invention, the basic catalyst of step (2) may be present in an amount of 0.03 to 0.1% based on the total weight of polyetheramine.

In one embodiment according to the present invention, the di(C _1-6 alkyl) maleate in step (2) may be diethyl maleate.

In addition, the method for preparing a polyaspartic ester compound according to the present invention may be performed by further including conventional steps known in the art before or after each step in addition to the above-described steps.

The method for preparing a polyetheramine-based polyaspartic ester using a microwave heating method according to an embodiment of the present invention rapidly heats a sample compared to a heating method using a conventional reflux device, so that the pretreatment time is short and the entire solution is uniform It has the advantage of being heated so that the reaction time can be shortened. In addition, since it reacts in an independent space that is cut off from external factors, it can prevent contamination of the sample and exposure of the experimenter to dangerous acids, thereby excluding risk factors that may occur during the reaction. Furthermore, the reaction using microwave can accurately measure the temperature and input inside the container to control the reaction conditions, thereby improving reproducibility and recovery.

The present reaction can produce polyetheramine based polyaspartic esters with a high yield of 99% or more in a short reaction time at a low temperature in the presence of a catalyst of 0.1% or less based on the total weight of the polyetheramine.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

First, a catalyst (Preparation Example 1) was prepared by the following method, and polyetheramines were prepared using the catalyst in Examples 1 to 4, and then polyaspartic esters were prepared.

Preparation Example 1

A spherical γ-Al ₂ O ₃ by heat treatment at 600 ℃ for 6 hours the catalyst support 235.5 m ² / g of specific surface area and acid site to have mesopore distribution of the γ-Al ₂ O ₃ 100% of the total carrier pore volume Used.

The precursors of each metal were weighed as follows in a desired mass ratio. Cobalt(II) nitrate hexahydrate (Purity, 98%) 26 g Yttrium nitrate hexahydrate (Purity, 99.999%) is 6 parts by weight based on 100 Cobalt precursor weight ratio, Palladium(II) nitrate dihydrate (Purity, 14.47%) is Cobalt precursor weight ratio 100 Each precursor was prepared to contain 0.1 parts by weight of the reference. The prepared precursors were all mixed and dissolved in 70 g of 1M HCl solution. After stirring for 2 hours to completely dissolve the mixed precursor solution, it was impregnated with 100 g of γ-Al ₂ O ₃ carrier. The precursor was dried in a 130° C. oven for 12 hours to remove moisture from the supported catalyst. The dried catalyst was heat treated at 350° C. for 6 hours to complete the final catalyst.

Example 1

A high pressure reactor equipped with a stirrer was charged with 58.8 g of the catalyst obtained in Preparation Example 1, and 294 g of polypropylene glycol (PPG) as a reaction raw material. After replacing the atmosphere in the high-pressure reactor with nitrogen at room temperature, hydrogen gas was introduced into the high-pressure reactor at about 50 bar and the internal temperature of the high-pressure reactor was increased to 220° C. to perform a catalyst pretreatment step for 2 hours. Through this catalyst pretreatment step, Cobalt oxide was reduced to Cobalt metal so as to have activity in preparing polyetheramine (PEA) from polypropylene glycol. After the catalyst pre-treatment step, 100 g of ammonia in the liquid state is added, then hydrogen is added so that the pressure inside the high-pressure reactor is 50 bar, and then the temperature inside the high-pressure reactor is increased to 220° C. and reacted for 2 hours to react polyetheramine from polypropylene glycol. Was prepared. The resulting polyetheramine was measured for amine conversion (Total amine, %) in the product through titration.

The above reaction was performed by irradiating microwaves to a mixture solution of 294 g of polyetheramine prepared above and 0.58 g of pyridine and 50.62 g of diethyl maleate at 40°C for 60 minutes at a frequency of 2.4 GHz, thereby performing polyetheramine-based polyaspartic The ester yield (the ratio to the theoretical amount of the amount actually obtained in the case of obtaining the target material polyaspartic ester (PAE) from the raw material polyetheramine (PEA)) was measured.

Example 2

In Example 1, a polyaspartic ester was prepared in the same manner as in Example 1, except that the reaction temperature was set to 60°C and the reaction time to 40 minutes during microwave irradiation.

Example 3

In Example 1, the polyaspartic ester was prepared in the same manner as in Example 1, except that the reaction temperature was set to 80°C and the reaction time to 20 minutes during microwave irradiation.

Example 4

In Example 1, a polyaspartic ester was prepared in the same manner as in Example 1, except that the reaction temperature was set to 100°C and the reaction time to 5 minutes during microwave irradiation.

Table 1 shows the results according to Examples 1 to 4 above.

As can be seen from the above examples, the method for preparing a catalyst according to the present invention is simplified, and a 99% or more from the reductive amination reaction of polypropylene glycol is utilized by utilizing a new catalyst to which a carrier having a form that is easily used repeatedly is applied. It is possible to obtain a polyetheramine having an amine value (Amine Value), from which a microwave heating method is utilized within 1 hour at a temperature of 100°C or less in the presence of a basic catalyst of 0.1% or less based on the total weight of the polyetheramine. , It is possible to prepare a polyetheramine-based polyaspartic ester with a high yield of 99.7% or more.

Since the specific parts of the present invention have been described in detail above, it is obvious to those skilled in the art that this specific technique is only a preferred embodiment, and the scope of the present invention is not limited thereby. something to do. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (7)

(1) in the presence of a catalyst for a reductive amination reaction and hydrogen, contacting polypropylene glycol (PPG) with an amine compound to produce polyetheramine (PEA); And
(2) mixing the polyetheramine produced in step (1) with a di(C _1-6 alkyl) maleate in the presence of a basic catalyst to heat react, and polyaspara to polyetheramine input weight. A method for producing a polyaspartic ester, wherein the time for the yield of the polyaspartic ester (PAE) to reach 99.5% or more is 5 to 60 minutes. According to claim 1, wherein the catalyst for the reductive amination reaction is a cobalt (Co) compound, a yttrium (Y) compound and a palladium (Pd) compound of 180 to 250 m ² /g specific surface area and 330 to 400 m ² / g meso A method for producing a polyaspartic ester, which is supported on a spherical γ-Al ₂ O ₃ carrier having a pore surface area. According to claim 2, Cobalt metal in the catalyst for the reductive amination reaction is contained in an amount of 1 to 12% by weight based on the weight of the carrier, yttrium metal is an amount of 0.05 to 30% by weight based on the weight of the cobalt metal It is contained, and the palladium metal is contained in an amount of 0.01 to 50% by weight based on the weight of the cobalt metal, a method for producing a polyaspartic ester. The method of claim 1, wherein the heating reaction in step (2) is performed while irradiating a microwave of 2.0 to 8.0 GHz. The method of claim 1, wherein the basic catalyst of step (2) is pyridine (pyridine), sodium hydroxide (NaOH), barium hydroxide (Ba(OH) ₂ ), sodium ethoxide, sodium ethoxide, piperidine ), 2,4,6-tri(dimethylamiomethyl)phenol (2,4,6-tris(dimethylaminomethyl)phenol) and triphenylphosphine, at least one member selected from the group consisting of polyetheramine It is present in 0.03% to 0.1% based on the total weight of the method for producing a polyaspartic ester. The method of claim 1, wherein the di(C _1-6 alkyl) maleate in step (2) is diethyl maleate. The method of claim 1, wherein the total amine value of the polyetheramine added to the step (2) is 99% or more.

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