JPH0248560A - Production of aldimine or ketimine - Google Patents

Abstract

PURPOSE:To obtain the title high-purity compound useful as a curing agent for epoxy resin, etc., in high yield while suppressing discoloration and by- products by reacting a primary amino compound with an aldehyde or ketone in the presence of boric acid and a boric acid derivative. CONSTITUTION:A primary amino compound (e.g., monoamine such as C14H29NH2 or alkanolamine such as COCH2CH2NH2) is reacted with an aldehyde (e.g., aliphatic aldehyde such as C2H5CHO) or ketone (e.g., CH3COCH3) in the presence of boric acid and a boric acid derivative (e.g. metaboric acid or tetraboric acid) to give aldimine or ketimine. The amount of boric acid or the boric acid is usually 0.005-2%, preferably 0.01-0.5wt.% based on the total amounts of the primary compound and the aldehyde and ketone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel method for producing aldimine or ketimine. More specifically, the aldimine or ketimine can be used as an epoxy resin curing agent, a urethane resin modifier, a polyamide resin modifier, or an agent for producing these agents.

[Prior Art] When synthesizing or purifying aldimines or ketimines, the amine compound and the aldehyde or ketone must be exposed to heating conditions. It is known that certain chemical compounds, particularly amines, undergo oxidation upon exposure to air or metal cations under heated conditions; this oxidation colors the amines red, yellow, or brown. A method of adding sodium borohydride or the like to prevent these colors is known (for example, JP-A-59-25355, JP-B-Sho 63-27330).

[Problems to be Solved by the Invention] The conventional method of adding sodium borohydride to prevent coloring is to decolorize the colored substance that has been formed using generated hydrogen; cannot be suppressed. In addition, exposing an amine compound and an aldehyde or ketone under heating conditions to carry out a reaction,
When exposed to heating conditions during distillation of aldimines or ketimines for purification, high molecular weight products may be produced. It has become necessary to simultaneously suppress the formation of this colored substance and high molecular weight separate products.

[Means for Solving the Problems] The present inventors have intensively studied a new method for producing aldimine or ketimine, and as a result, have arrived at the present invention.

That is, the present invention is a method for producing aldimine or ketimine, which is characterized by reacting a primary amino compound with an aldehyde or ketone in the presence of boric acid and/or a boric acid derivative.

Examples of boric acid derivatives include metaboric acid, tetraboric acid, metal salts, amine salts, ammonium salts, and mixtures thereof. Specific examples include boric acid, metaboric acid, tetraboric acid and their metal salts (alkali metals such as Ll+Na and salts, alkaline earth metals such as Ca
and Mg salts, other elements such as Z no A I
amine salts (alkylamine salts such as methylamine, dimethylamine salts, alkanolamine salts such as triethanolamine salts), ammonium salts (ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium heborate) Such)
, boron oxide, boron complex compound (C(Ca[l5O)J
] II, etc.), borate esters (monomethyl borate,
dimethyl borate, trimethyl borate, monoethyl borate, diethyl borate, triethyl borate, monophenyl borate, diphenyl borate, triphenyl borate, etc.), or mixtures thereof.

The aldimine or ketimine in the present invention can be produced by heating and stirring a primary amino compound and an aldehyde or ketone in the absence of a catalyst or in the presence of a catalyst to dehydrate them.

The primary amino compound used in the present invention includes monoamines such as C+4+1asNB+C+s■31N■2
+Cl6Ha3N■a, Cv HT N112.0+
s 117 NHa, alkanolamines such as tlOclI2CH* NHa, polyamines such as NH2C■2CH2NHCH2CHJH*, NH
aCH2CII*CH2NHCH2C)I2NH21N
H2CFitCH2C■2 N11ICIIIt CH
Examples include compounds represented by + CH2NH2.

Examples of aldehydes include aliphatic aldehydes such as Ct H
sCtlO, Cs L C[Q, Catl*CI(O
,c,L ICBO,C61113C110,CtB
+ 5(JO, CaIIt 7cHo, CsL *l
JO, CI 1121 CHO, CH12*CHO2C
22■21IcHO,C+5H2tCtlO,Ca J
a*C[IO, C+sHs+C■O, Ca eHs3C
Aliphatic dialdehydes such as CHOC2H4CHO, aromatic aldehydes such as C65cHo, C3yHiCHO, HOCs
Examples include compounds represented by heterocyclic aldehydes such as C, 1I30cHo, etc., such as H4CHO, C+@HtC■0, etc.

Ketones include aliphatic ketones such as C113CO-C
112, CH3Go-02Hs, CI3GO-Cs
Hv, C113Co-C4)IQ, CHsCo
-Cs H+ 1. CHsCo-CoH+s,
C2■5co-C2Hs, CaHsCO-C3Hv
, CJsCO-CaFlm, CaHsCO-Cs■th, C2HsCO-C6■Ia+C3■tcO-Cd7,
Cs1ftGO-04H*, C3■? C0-C3HI
I, CaHsCO-Cs[IIi, Ca■CQ-
CaFi@, CJsCO-Cs■口+CaHoC0-
CJH+z *C5HIICO-CsH ro, CsH++
GO-Co■+s 1c6HI3co-C6H13, etc., aromatic ketones such as CaHsCO-CHs, C5
HsCO-C2Hs, CaTi6GO-Cs117,
C@Ha C0-Ca Ha, Co Is C0-
Cs Hs +Ca Hs CHs Co-CH2Cs
Examples include compounds represented by Hs and the like.

The amount of boric acid or boric acid derivative added is usually 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 where added based on the total weight of the primary amino compound and aldehyde or ketone;
0.005-2%, preferably 0.01-0.5%.

The ratio of the primary amine compound to the aldehyde or ketone used is usually 1 to 3 equivalents, preferably 1.1 to 2.2 equivalents, per equivalent of the primary amino compound.

The reaction temperature between the primary amine compound and the aldehyde or ketone varies depending on the amino compound used and the type of aldehyde or ketone, but is usually 50 to 150"C, preferably 7G to 130"C.

The reaction pressure is usually I Kg/am" ~ -500 cmH
Ih is preferably 1 to -20 cmHg.

The reaction time is usually 0.5 to 10 hrs.

Aldimines or ketimines can be purified by distillation. If the boric acid or boric acid derivative added during the reaction is left intact during distillation, the formation of colored substances and high molecular weight by-products can be suppressed, and high purity aldimine or ketimine can be produced with good yield. I can do it.

[Examples] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto. In the following, parts and % indicate parts by weight and % by weight, respectively.

Comparative Example 1 5 with a stirrer, thermometer, nitrogen blowing tube, and reflux condenser tube
L 4 Turocolben and diethylenetriamine 788
g and 2,830 g of methyl isobutyl ketone were added, stirring was started while nitrogen was being blown into the mixture, and the temperature was raised to 100°C. The distilled azeotropic mixture of diethylenetriamine and water was passed through a reflux condenser to separate water, and the reaction proceeded while refluxing methyl isobutyl ketone. It took 8 hours until 275 g of water came out and the reaction was completed.

The final temperature was 125°C. Thereafter, excess methyl isobutyl ketone was distilled off as much as possible at normal pressure and 100 to 125°C while blowing nitrogen, and then -7 [icmH
The residue was distilled off under reduced pressure. It was then cooled to 60"C and the yield was weighed. 1998g of brown crude 1.2 (clivia).

Tmin-N-(1,3-dimethylphthyrene)-N
'-[2-(1,3-dimethylbuderite)7mino]
Ethyl was obtained. Next, the reflux condenser was replaced with a Raschig distillation tube and a condenser, and the temperature was 75cm) Ig~-711gcmH.
g Distillation was performed under reduced pressure.

-145℃ fraction 90g (Purity 86.0% sieve method) 145-150℃ fraction 1537g (Purity 34.5%) 150-155℃ fraction 200g
(Purity 96.6%) Residue I at 155℃~
89g was obtained. Moreover, the distillate was colored pale yellow.

Example 1 5 with a stirrer, thermometer, nitrogen blowing tube, and reflux condenser
788g of diethylenetriamine in L 4 turocolben
, methyl isobutyl ketone 2830g, boric acid 4.0
Add g and start stirring while blowing nitrogen to 100°.
The temperature was raised to C. The distilled azeotropic mixture of diethylenetriamine and water was passed through a reflux condenser to separate water, and the reaction proceeded while refluxing methyl isobutyl ketone. It took 8 hours until 275 g of water came out and the reaction was completed. Final temperature 1
The temperature was 25°C. Thereafter, excess methyl isobutyl ketone was distilled off as much as possible at normal pressure at 100 to 125° C. while blowing nitrogen, and then the remainder was distilled off under a reduced pressure of -7 [icmHg]. Thereafter, it was cooled to BO° C. and the obtained amount was weighed. 2000 g of pale yellow crude 1,2-echundiamine (1,3-dimethylbutyrene)-N'-[2-
(l,3-dimethylbutyrite)aminocoethyl was obtained. Next, the reflux condenser tube was replaced with a Raschig distillation tube and a condenser tube, and distillation was carried out under a reduced pressure of -75 cmHg to -76 cmHg.

-145°C fraction 88g (purity 86.4% A method) 145-150°C fraction 1758g (purity 98.7%) 150-155°C fraction 100
g (purity 97.2%〃) Residue from 155℃
54g was obtained.

Comparative Example 2 5 with a stirrer, thermometer, nitrogen blowing tube, and reflux condenser
L 4 turocolben and monoethanolamine 978g
+ 3040 g of methyl isobutyl ketone was added, stirring was started while nitrogen was being blown into the mixture, and the temperature was raised to 100°C. The distilled azeotrope of diethylenetriamine and water was passed through a reflux condenser to separate water while the reaction proceeded. It took 7 hours until 288 g of water came out and the reaction was completed. Final temperature 1
The temperature was 25°C. Then add excess methyl isobutyl ketone to normal pressure at 100~! As much as possible was distilled off at 25° C. while blowing nitrogen, and then the remainder was distilled off under reduced pressure of 76 cm [1 g]. Thereafter, it was cooled to 60°C and the obtained amount was weighed. 2284 g of brown crude [2-(1,3-dimethylmethyltethane)aminocoethanol] were obtained.

Next, the reflux condenser was replaced with a Raschig distillation tube and a condenser, and distillation was carried out under reduced pressure of -75 cmHg to -7 [icm].

~90°C fraction 148g (purity 84.0% aqueous method) 90~35°C fraction 1898g (purity 9
5.2% 〃 ) 35-120°C fraction 231g
(Purity 95.9%〃) Residue at 120℃~ 207
g was obtained.

Example 2 5 with a stirrer, thermometer, nitrogen blowing tube, and reflux condenser
978g of monoethanolamine in L 4 turocolben
, methyl isobutyl ketone 3040g, boric acid 4.6
g and started stirring while blowing in nitrogen and heated to 100°C.
The temperature rose to . The distilled azeotrope of diethylenetriamine and water was passed through a reflux condenser to separate water while the reaction proceeded. It took 7 hours until 288 g of water came out and the reaction was completed. The final temperature was 125°C. Thereafter, excess methyl isobutyl ketone was distilled off as much as possible at normal pressure and 100-125°C while blowing nitrogen, and then -7 [i
The remainder was distilled off under reduced pressure of ca+Hg. then 60°C
The obtained amount was weighed. 2289g of light brown crude [
2-(1,3-dimethylbutyrite-mino)ethanol was obtained.Then, the reflux condenser was replaced with a Raschig distillation tube and a condenser, and distillation was carried out under reduced pressure from 175 cm [Ig to -76 cm11 g].

~30°C fraction 145g (purity 84.2% strength chromatography method) 30~95°C fraction 2041g (purity 98%)
．． 2%〃) 95~120℃ fraction 74g (purity 9B, 0%〃) 120℃~ residue [i9g [Effect of the invention]

Claims (1)

[Scope of Claims] 1. A method for producing aldimine or ketimine, which comprises reacting a primary amino compound with an aldehyde or ketone in the presence of boric acid and/or a boric acid derivative. 2. The production method according to claim 1, wherein the amount of boric acid and/or boric acid derivative added is 0.005 to 2% based on the total weight of the primary amino compound and aldehyde or ketone. 3. The manufacturing method according to claim 1 or 2, wherein metaboric acid, tetraboric acid, a metal salt thereof, an amine salt, an ammonium salt, or a mixture thereof is used as the boric acid derivative.