KR100537671B1 - Process for Preparing 3-[N-(2-aminoethyl)]aminoalkylalkoxysilanes - Google Patents

Abstract

The present invention relates to a process for the preparation of 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane. Specifically, 3-chloroalkylalkoxysilane, an excess of ethylenediamine and an aromatic azole catalyst are placed in a reactor at low temperature. After 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane was synthesized with good stirring in ethylenediamine, ethylenediamine and hydrogen chloride were added to the synthetic mixture to form a two-phase liquid layer. Removing the hydrogen chloride layer and then distilling the filtrate to remove the low boiling point component of ethylenediamine to prepare a high purity 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane in high yield.

The production method according to the present invention has the advantage that the production amount of the polyalkoxy compound by-produced during the production of conventional 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane is suppressed by preparing the compound at low temperature under a catalyst. Instead of the distillation step, an ethylenediamine-hydrogen chloride salt is added to the synthesized mixed solution and separated by easy separation, thereby simplifying the purification process of 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane.

Description

Process for Preparing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilanes}

3- [N- (2-aminoethyl)] aminoalkylalkoxysilanes are widely used as silane coupling agents and are useful for enhancing adhesion between organic and inorganic interfaces or for changing various polymer properties. 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane is prepared by reacting 3-chloroalkylalkoxysilane with ethylenediamine, which generates hydrogen chloride and polyalkylated chemicals as reaction by-products. Let's do it. Hydrogen chloride by-produced here reacts with ethylenediamine used as a reaction raw material to form ethylenediamine-hydrochloride, which is then removed by layer separation with 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane, but 3- [N A polyalkyl compound, a by-product produced by the reaction of-(2-aminoethyl)] aminoalkylalkoxysilane with starting materials 3-chloroalkylalkoxysilane and ethylenediamine, is 3- [N- (2-aminoethyl)] amino. It is a cause to reduce the production yield of alkylalkoxysilane.

Polyalkyl compounds produced as reaction by-products are usually difficult to remove during purification, and thus research has been conducted toward suppressing their production during the synthesis reaction. U.S. Patent 2,971,864 and Polish Patent 145,671 disclose the reaction of 3-chloroalkylalkoxysilane with ethylenediamine to prepare 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane. It was confirmed that one equivalent of 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane was formed together with ethylenediamine hydrogen chloride when synthesized using the equivalents and 2.5 equivalents of ethylenediamine. However, due to the production of polyalkyl compounds, there was a disadvantage in that the purity and yield in the final target material is low.

In an attempt to suppress the production of this polyalkyl compound, Japanese Patent Application Laid-Open No. 56-1185 discloses that 1 equivalent of 3-chloroalkylalkoxysilane and 4-6 equivalents of ethylenediamine are reacted at about 120 ° C. for 3 hours or more. [N- (2-aminoethyl)] aminoalkylalkoxysilane was prepared, but in order to suppress the polyalkylalkoxysilane which is a side reaction substance and to raise the yield of 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane sufficiently, It was still lacking and the best yield was only 61%.

In Japanese Patent Application Laid-Open No. 56-104891, 1 equivalent of 3-chloropropylalkoxysilane and 7-10 equivalents of ethylenediamine are reacted for 1 hour at around 120 DEG C, so that 1 equivalent of 3- [N- (2-aminoethyl) ] When aminopropyl alkoxysilane was produced, the target material was obtained in 88% yield, suppressing the production amount of the polyalkyl compound which is a side reaction product to about 2%. However, this method has a disadvantage in that the process is somewhat complicated to recover the ethylenediamine used after the reaction, and the reaction temperature is not high enough to suppress side reactions.

U.S. Patent No. 5,446,181 discloses that 3-chloropropylalkoxysilane and at least 12 equivalents of ethylenediamine are reacted at 80 to 100 DEG C using a U-type reactor including an ethylenediamine distillation unit and an ethylenediamine reflux unit. -Aminoethyl)] aminopropylalkoxysilane, the target material was obtained in 99.4% purity and 91% yield, and the semi-continuous operation has the advantage of high productivity, but the manufacturing reactor had a complex disadvantage, reaction The site temperature (90 ° C) and distillation temperature (120 ° C or more) had a disadvantage of increasing the production of polyalkyl compounds.

US Patent No. 6,452,033, on the other hand, reuses the ethylenediamine-hydrochloride salt layer which is a byproduct when reacting 3-chloroalkylalkoxysilane and ethylenediamine to produce 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane. By developing a two-phase in the reactor to suppress the production of polyalkyl compounds. Ethylenediamine is here known to have obtained a conversion of 99.1% and the same yield as using pure ethylenediamine when held at 105 ° C. for 68 minutes using 12 equivalents. After the reaction, the ethylenediamine-hydrochloride salt layer is separated from the alkoxysilane layer without removing ethylenediamine by distillation, and thus the distillation step is omitted. The disadvantage is that the production is not sufficiently suppressed.

Therefore, the present invention employs low-temperature reaction conditions to minimize the production of by-product polyalkyl compounds, while the reaction yield is high and the separation process is simplified and economical and stable 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane It is intended to provide a method for preparing the same.

The present invention relates to an effective process for the preparation of 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane, specifically to reacting with 3-chloroalkylalkoxysilane and excess ethylenediamine to prepare the material. In the process of preparing-[N- (2-aminoethyl)] aminoalkylalkoxysilane, the reaction temperature is lowered by using an aromatic azole compound such as imidazole as the reaction catalyst, thereby reducing 3- [N- (2 -Aminoethyl)] ethylenediamine hydrogen chloride containing ethylenediamine by-produced from the synthesis after inhibiting the production of by-product polyalkyl compounds in production of aminoalkylalkoxysilane and maximizing the synthesis purity and production yield of the target compound. Was added to the synthesis mixture to induce the formation of two phases and the lower layer of ethylenediamine / hydrochloride was removed from the phase separation vessel with 3- [N- (2) containing ethylenediamine. -Aminoethyl)] aminoalkylalkoxysilane layer is left, and the filtrate is transferred to a distillation apparatus to remove ethylenediamine and alcohol by distillation operation to effect 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane and It relates to a method of manufacturing economically.

When explaining the present invention in detail, a 3-chloroalkylalkoxysilane represented by the following formula (1) and an amine catalyst together with ethylenediamine in a reactor to react 3- [N- (2-aminoethyl)] amino represented by the formula (2) It is a manufacturing method characterized by manufacturing an alkylalkoxysilane.

[Formula 1]

Cl (CH ₂ ) _a Si (R ¹ ) _3-n (OR ² ) _n

[Formula 2]

NH ₂ CH ₂ CH ₂ NH (CH ₂ ) _a Si (R ¹ ) _3-n (OR ² ) _n

In Formula 1 and Formula 2, a is an integer of 3 or 4, n is an integer of 1 to 3, R ¹ and R ² may be the same or different and represent a methyl group or an ethyl group.

Specific examples of the 3-chloroalkylalkoxysilane compound represented by the formula (1) used in the present invention include 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 4-chlorobutyltrimethoxysilane, 4- Chlorobutyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyldimethylmethoxysilane, and the like, and the compounds exemplified above do not limit the scope of the present invention.

In addition, 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane compound represented by the formula (2) is 3- [N- (2-aminoethyl)] aminopropyltrimethoxy silane, 3- [N- ( 2-aminoethyl)] aminopropyltriethoxysilane, 4- [N- (2-aminoethyl)] aminobutyltrimethoxysilane, 4- [N- (2-aminoethyl)] aminobutyltriethoxysilane , 3- [N- (2-aminoethyl)] aminopropylmethyldimethoxysilane, 3- [N- (2-aminoethyl)] aminopropyldimethylmethoxysilane, and these examples limit the present invention. no.

Ethylenediamine to be used on a 1 mole basis of 3-chloroalkylalkoxysilane is preferably 8 to 12 moles, particularly preferably 9 to 11 moles. When the amount of ethylenediamine is lower than 8 molar ratio, the production amount of by-product polyalkyl compound is increased. When the amount of ethylenediamine is higher than 12 molar ratio, the production amount of polyalkyl compound is insignificant, while the recovery cost of used ethylenediamine is increased and manufacturing productivity is decreased. Done.

Aromatic azole catalysts include imidazole and triazole, and especially 1,3-imidazole is preferred, but the above examples do not limit the scope of the present invention. The amount of the catalyst is preferably used 1 to 20000 ppm based on 3-chloroalkoxysilane.

Although most of the conventional methods for preparing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane have been prepared at a reaction time of 1 to 3 hours even at a reaction temperature of 90 to 120 ° C, in the present invention, aromatic 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane could be effectively prepared even at a relatively low temperature of 50 ° C. to 80 ° C. using an azole catalyst. In particular, the low reaction temperature was able to suppress the production of polyalkyl compounds. If the reaction temperature is 50 ° C or less, the reaction rate is slow, the production productivity is lowered, and if the reaction temperature is 80 ° C or more, the production amount of the polyalkyl compound is increased and the yield is lowered. The reaction heat generated during the reaction can be cooled with external cooling water and the reaction rate can be controlled. The reaction is preferably carried out under atmospheric pressure using an open reactor to release the waste gas stream generated during the reaction.

It is possible to maximize the yield of the target compound while suppressing the polyalkyl compound by reacting it at once or by plugging the reaction rather than dropwise during the reaction. Yield can be maximized.

The process for preparing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane according to the present invention is described in detail in a three-necked round flask with a thermometer attachment, reflux cooler attachment, nitrogen and reactant inlet. The reaction is started by adding chloroalkylalkoxysilane, ethylenediamine, aromatic azole catalyst and raising the reaction temperature to 50 ° C while stirring well with a magnetic stirrer. Due to the exotherm generated during the reaction, the reaction temperature starts at 50 ° C and rises to around 70 ° C. The reaction time was run for 1 hour and 30 minutes to complete the reaction. 20% of ethylenediamine-hydrogen chloride containing ethylenediamine is added on a total reactant basis so that the reaction solution is separated into two phases. Remove the lower layer of ethylenediamine / hydrochloride salt containing ethylenediamine with separatory funnel, transfer the upper layer to the distillation unit and remove low boiling point such as ethylenediamine and alcohol under 60 ~ 70 ℃ temperature and 1 ~ 600 torr vacuum. -[N- (2-aminoethyl)] aminoalkylalkoxysilane was obtained as a filtrate and identified as a substance using a nuclear magnetic resonance analyzer and a gas chromatography analyzer.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

EXAMPLE

The 1 liter three-necked round flask with thermometer, reflux condenser and nitrogen inlet was well dried and replaced by nitrogen atmosphere, followed by 150 g of 3-chloropropylmethoxysilane, 450 g of ethylenediamine, and 0.30 g (2000 ppm) of 1,3-imidazole. Put each into the flask and while stirring well with a magnetic stirrer to increase the temperature of the reactants to 50 ℃ in a hot plate at the bottom of the reactor to proceed the reaction slowly. When the reaction proceeds, even if the hot plate is removed, the reaction temperature increases with the heat of reaction, increasing the reaction rate. The outside of the flask was cooled with a water bath and allowed to react for 1 hour while the reaction temperature did not exceed 70 ° C., followed by another 30 minutes to complete the reaction. 120 g of a mixture of 60:40 ethylenediamine to ethylenediamine / hydrogen chloride is added to the reaction mixture, stirred well, and left to stand in two phases. Transfer this mixture to a 1L separatory funnel and leave for a while to check for complete separation. When the mixture layer of cloudy viscous ethylenediamine and ethylenediamine hydrogen chloride is removed, a mixture layer of transparent ethylenediamine and 3- [N- (2-aminoethyl)] aminopropyltrimethoxy silane is left as a filtrate. Is transferred to a 1 L distillation flask and heated to 70 DEG C while stirring well with a magnetic stirrer, and maintained at this temperature while varying the vacuum from 600 to 50 torr to lower the boiling point of methanol and ethylenediamine. The filtrate was confirmed to be 97% pure 3- [N- (2-aminoethyl)] aminopropyltrimethoxy silane by gas chromatography and nuclear magnetic resonance analyzer. The filtrate was 157 g and the yield was 94%.

The process for preparing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane according to the present invention is a by-product by reacting 3-chloroalkylalkoxysilane and excess ethylenediamine at an relatively low temperature using an aromatic azole catalyst. 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane was synthesized in high purity while suppressing the formation of the polyalkyl compound, and ethylenediamine / hydrogen chloride was added after the synthesis to separate into two phases without going through a distillation step. The manufacturing process has a simplified advantage, and the effective separation of the lower ethylenediamine-hydrogen chloride layer and then remove the low boiling point component through vacuum distillation has the effect of providing a method for producing a target compound in a high yield.

Claims (6)

In the method for preparing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane, an aromatic azole catalyst is reacted with 3-chloroalkylalkoxysilane represented by the following formula (1) and ethylenediamine to react with 3- [ N- (2-aminoethyl)] aminoalkylalkoxysilane is synthesized, Ethylenediamine and an ethylenediamine-hydrochloride salt mixture were added to the synthesized mixture to form a two-phase separation and separation. The ethylenediamine-hydrochloride salt layer was removed, and the filtrate was distilled to obtain 3- [N- ( 2-aminoethyl)] aminoalkylalkoxysilane. [Formula 1] Cl (CH ₂ ) _a Si (R ¹ ) _3-n (OR ² ) _n [Formula 2] NH ₂ CH ₂ CH ₂ NH (CH ₂ ) _a Si (R ¹ ) _3-n (OR ² ) _n [In Formula 1 and Formula 2, a is an integer of 3 or 4, n is an integer of 1 to 3, and R1 and R2 may be the same or different and represent a methyl group or an ethyl group.] The 3-chloroalkylalkoxysilane compound represented by the formula (1) according to claim 1 is 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 4-chlorobutyltrimethoxysilane, 4-chlorobutyltri A process for producing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane, which is selected from ethoxysilane, 3-chloropropylmethyldimethoxysilane and 3-chloropropyldimethylmethoxysilane. The method for producing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane according to claim 1, wherein the aromatic azole catalyst compound is selected from imidazole and triazole. The process for producing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane according to claim 3, wherein the aromatic azole catalyst compound is 1,3-imidazole. The method for producing 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane according to claim 4, wherein the molar ratio of ethylenediamine and 3-chloroalkylalkoxysilane is used in an amount of 8 to 12 moles. To separate into two phases according to claim 1, ethylenediamine and hydrogen chloride salts are synthesized and added to the mixed solution to form a two-phase liquid layer to prepare 3- [N- (2-aminoethyl)] aminoalkylalkoxysilane. Manufacturing method.