1. A process for the preparation of an alkanolamine of formula I, the process comprising the steps of:

wherein n is an integer of 1-11;

liquid ammonia, diepoxide of formula 1 in catalyst CuI and catalyst promoter ZrO₂And an amine additive to form an intermediate of formula 2, and then further reacting with ethylene oxide to form an alkanolamine of formula I.

2. The method according to claim 1, wherein liquid ammonia, the diepoxide of formula 1, the catalyst CuI, and the cocatalyst ZrO are added to the reaction vessel₂And amine additives, replacing air in the amine additives with nitrogen, sealing the reaction kettle, heating to 50-80 ℃, and reacting for 1-12 hours; then introducing ethylene oxide gas into the reactor, raising the reaction temperature to 70-100 ℃, and keeping the pressure in the reactor at 0.2-1.0 Mpa for continuing the reaction for 3-15 h; and (3) filtering and recovering the catalyst while the catalyst is hot after the reaction is finished, and rectifying the filtrate to obtain the alkanolamine of the formula I.

3. The method according to claim 1 or 2, wherein n is 1 to 5, preferably n is 1, 3 or 5.

4. The method according to claim 1 or 2, wherein the amine additive is selected from tertiary amines, preferably at least one selected from pyridine, tri-n-butylamine, tetramethylethylenediamine, and hexamethylenetetramine.

5. The production method according to claim 1 or 2, characterized in that liquid ammonia, the diepoxide of formula 1, the catalyst CuI, the cocatalyst ZrO₂And the molar ratio of the amine additive is as follows: 2.0-2.6: 1: 0.01-0.12: 0.002-0.06: 0.004-0.08.

6. The synthesis method according to claim 1, wherein the pressure in the reaction vessel is maintained at 0.25 to 0.5MPa, preferably 0.28 to 0.35 MPa.

7. The process according to claim 2, wherein the recovered catalyst is stirred with dilute hydrochloric acid, filtered and washed with ethanol, and then vacuum-dried to activate, and added to the starting mixture of the reaction for use.

8. The preparation method according to claim 7, characterized in that the activated catalyst and the fresh catalyst are mixed according to a mass ratio of 0.1-1.5: 1, and mixing and using.

9. The preparation method according to claim 2, wherein the filtrate is gradually heated to 100-170 ℃ under a vacuum degree of 1-100 mmHg during rectification, and the mixture of ethanolamine and diethanolamine is recovered.

10. The method according to claim 9, wherein the recovered mixture of ethanolamine and diethanolamine is added to the starting mixture of the reaction.

Background

The alkanolamine is a compound in which 1 to 3 hydrogen atoms on a nitrogen atom in an ammonia molecule are substituted with a hydroxyalkyl group having 2 to 4 carbon atoms, such as a hydroxyethyl group, a hydroxypropyl group, or the like. Typical alkanolamines include diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, diethanolisopropanolamine, N- (2-hydroxypropyl) -N- (hydroxyethyl) amine, and the like. The alkanolamine is an important chemical product and is mainly used as a concrete additive, a cement additive, a metal cutting fluid, a cooling fluid, an antirust fluid, an acid-base neutralizer, an emulsifier, an ink, a surfactant, a complexing agent, an acid gas absorbent and the like.

Alkanolamines, particularly alkyl ethanolamines, are typically obtained by reacting a primary or secondary amine with an epoxide (e.g., ethylene oxide) such as in the following reaction:

the efficiency with which the reaction proceeds varies depending on the reaction conditions, in particular the catalyst of the reaction.

DE1941859.8 describes a process for the selective synthesis of monoalkanolamine from epoxides and ammonia in the presence of cation exchange resins. To optimize the use of the apparatus, the temperature of the catalyst reaction column and the flow rate of the reaction mixture through the catalyst were set to achieve the highest yield of monoethanolamine per unit time. EP0652207 discloses a selective synthesis process for preparing monoalkanolamine from epoxides and ammonia in the liquid phase, using a catalyst comprising a rare earth element applied to a heat-resistant support. EP09411986 describes a process for preparing dialkanolamines starting from an epoxide and ammonia. Wherein a zeolite catalyst is used. Here again the temperature at which the reaction occurs is only roughly determined by the oil bath temperature. DD298636 describes a process for the preparation of diethanolamine by reaction of ammonia with ethylene oxide in the gas phase, wherein the catalyst used is a heterogeneous catalyst: a pentasil-type crystalline silicate. DE2547328 describes a process for the continuous preparation of dialkanolamines, in which an epoxide is contacted with ammonia in a first reaction stage, the monoalkanolamine formed is separated off from the material discharged from the first reaction stage, and the separated monoalkanolamine is contacted with an olefin oxide in a second reaction stage. The preparation of trialkanolamines is adjusted by establishing the molar ratio of monoalkanolamine to olefin oxide, the reaction being carried out in the absence of catalyst and water. Furthermore, for catalysis with noble metals, EP 239934; marsella, J.org.chem.1987,52,467- -; US 4855425; K. -t.huh, bull.kor.chem.soc.1990, 11, 45-49; n.andrushko, v.andrushko, p.roose, k.moonen, a.chemcatchem,2010,2,640-643 and s.a.tillack, s.imm, k.mevius, d.michallik, d.hollmann, l.neubert, m.beller, ChemSusChem 2009,2,551-557 describe techniques for reacting secondary amines with diols using homogeneous iridium and ruthenium catalysts to form aminoalcohols having tertiary amino groups and linear diamines. EP0234401 describes the reaction of ethylene glycol with ammonia in the presence of ruthenium carbonyl compounds which leads in particular to the monoamination product (monoethanolamine) and, in addition, to the formation of a large number of secondary and tertiary amines (diethanolamine and triethanolamine) and cyclic products (N- (hydroxyethyl) piperazine and N, -di (hydroxyethyl) piperazine) as by-products.

However, the alkanolamines thus prepared suffer from discoloration problems during distillation and/or during storage, which discoloration is due to the presence of conjugated unsaturated impurities and/or carbonylated derivatives. US2004/0110988, US6291715, EP0632013, EP0477593, EP2445863 have described different treatments to limit this problem of alkylethanolamine coloration. In order to inhibit compounds capable of imparting coloration, the prior art has proposed the use of reducing agents (e.g. hydrogen, NaBH)₄Etc.) work-up of the reaction crude product, or alkanolamine distilled beforehand, or seek other alternatives avoiding the use of epoxy compounds.

Furthermore, the processes for preparing alkanolamines reported in the prior art are mostly based on monoamine compounds, and the prior art is rarely concerned with the synthesis of alkanolamines with diamines, in particular linear alkylene diamines, as cores. In conclusion, there is still much room for improvement in the process for producing alkanolamines, and in particular, how to produce alkanolamines, particularly alkanolamines having a core of a linear alkylenediamine, of high quality in high yield at low cost is still a problem to be solved.

Disclosure of Invention

In order to solve the problems of the prior art, the present invention provides a process for producing a linear alkylenediamine-cored alkanolamine which is suitable for industrial production of the alkanolamine, by using a liquid amine, a linear diepoxide, and ethylene oxide as raw materials, and by using a specific combination of a catalyst and additives, an alkanolamine having a high purity and a low color number is obtained in a high yield, and the process is simple and easy to produce on a large scale.

Specifically, the present invention provides a process for the preparation of an alkanolamine of formula I, comprising the steps of:

wherein n is an integer of 1-11;

liquid ammonia, diepoxide of formula 1 in catalyst CuI and catalyst promoter ZrO₂And an amine additive to form an intermediate of formula 2, and then further reacting with ethylene oxide to form an alkanolamine of formula I.

Specifically, the method of the invention comprises the following steps: adding liquid ammonia, diepoxide of formula 1, catalyst CuI and cocatalyst ZrO into a reaction kettle₂And amine additives, replacing air in the amine additives with nitrogen, sealing the reaction kettle, heating to 50-80 ℃, and reacting for 1-12 hours; then introducing ethylene oxide gas into the reactor, raising the reaction temperature to 70-100 ℃, and keeping the pressure in the reactor at 0.2-1.0 Mpa for continuing the reaction for 3-15 h; and (3) filtering and recovering the catalyst while the catalyst is hot after the reaction is finished, and rectifying the filtrate to obtain the alkanolamine of the formula I.

Preferably, in the method of the present invention, n may be 1, 2, 3, 4, 5, 7, 8, 9, 10 or 11. Preferably, n is 1-5; more preferably, n is 1, 3 or 5.

Preferably, the alkanolamine of formula I may be:

(1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-ol) or

(1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol).

Preferably, in the method of the present invention, the amine additive is selected from tertiary amines, and specifically may be selected from at least one of pyridine, tri-n-butylamine, tetramethylethylenediamine and hexamethylenetetramine. Preferably, the amine additive is selected from hexamethylenetetramine. In the invention, the amine additive has the functions of reducing the generation of colored impurities and improving the purity and chromaticity of the product. In the absence of amine additives, the quality of the obtained alkanolamine is obviously deteriorated, the purity of the product is reduced, and the chroma value is increased.

Preferably, in the process of the present invention, liquid ammonia, the diepoxide of formula 1, the catalyst CuI, and the cocatalyst ZrO₂And the molar ratio of the amine additive is as follows: 2.0-2.6: 1: 0.01-0.12: 0.002-0.06: 0.004-0.08. Preferably, the molar amount of liquid ammonia compared to the molar amount of diepoxide of formula 1 is: 2.1 to 2.4, preferably 2.2 to 2.3; the relative molar amounts of catalyst CuI are: 0.02 to 0.10, preferably 0.04 to 0.06; promoter ZrO₂The relative molar amounts of (A) are: 0.004-0.04, preferably 0.008-0.02; the relative molar ratio of the amine additive is as follows: 0.008 to 0.03, preferably 0.01 to 0.02.

Preferably, in the process according to the invention, the catalyst CuI is used together with a promoter ZrO₂In a molar ratio of 1: 0.1-1.0, preferably, the molar ratio is 1: 0.2 to 0.8, more preferably 1: 0.3 to 0.5. CuI has strong catalytic activity, and ZrO has₂The surface has both acidity and alkalinity, so that the catalyst also has oxidation property, reduction property and better catalytic activity. In the method of the invention, the two are combined with each other to ensure that the activity of the catalyst system is higher and the reaction is more thorough.

Preferably, in the method of the present invention, the reaction temperature of the previous step is 60 to 70 ℃.

Preferably, in the method of the invention, the reaction temperature of the latter step is 80-95 ℃.

Preferably, in the method of the present invention, the pressure in the reaction kettle in the latter step is maintained at 0.25 to 0.5MPa, preferably 0.28 to 0.35 MPa.

Preferably, in the process according to the invention, the recovered catalyst can be reused in the catalysis of the reaction. More preferably, the recovered catalyst may be used again in the catalysis of the reaction after being activated, which includes washing the recovered catalyst with diluted hydrochloric acid, filtering and washing with ethanol, and then vacuum-drying. After reactivation, the catalyst may have an activity almost comparable to that of a fresh catalyst.

Preferably, the mass ratio of the activated catalyst to the fresh catalyst is 0.1-1.5: 1, and more preferably, the ratio can be 0.3-1.0: 1, or 0.4-0.6: 1.

preferably, in the method, the filtrate is gradually heated to 100-170 ℃ under the vacuum degree of 1-100 mmHg during rectification, and the mixture of the ethanolamine and the diethanolamine is recovered; preferably, the filtrate is gradually heated to 120-160 ℃ under the vacuum degree of 5-20 mmHg. Preferably, the recovered mixture of ethanolamine and diethanolamine is added to the starting mixture of the reaction. Since ethanolamine and diethanolamine have higher reactivity than liquid ammonia, they are first reacted with the diepoxide of formula 1 during the reaction to form the alkanolamine of formula I, or for example, a compound lacking one or two 2-hydroxyethyl groupsAnd intermediate compounds which may subsequently be further reacted with ethylene oxide to also be converted into alkanolamines of formula I. Thus, the process of the present invention has a high atom economy.

In another aspect, the invention provides the use of an alkanolamine of formula I in a mineral fines enhancer or a fly ash activator.

In another aspect, the invention provides a mineral fines enhancer or fly ash activator comprising an alkanolamine of formula I.

Preferably, the mineral powder enhancer comprises: 50-78 parts of Na₂SO₄10-30 parts of NaAlO₂And 8-22 parts of an alkanolamine of formula I.

Preferably, the fly ash activator comprises: 45-64 parts of calcium sulfate, 8-20 parts of potassium carbonate, 10-25 parts of sodium silicate and 6-20 parts of alkanolamine shown in the formula I.

In another aspect, the present invention provides a mineral powder cement comprising: 25-75 parts of portland cement clinker and 25-75 parts of mineral powder; and the addition amount of the mineral powder reinforcing agent is 0.1-6% of the total amount of the portland cement clinker and the mineral powder.

In another aspect, the present invention provides a fly ash cement comprising: 40-85 parts of Portland cement clinker and 15-60 parts of fly ash; and the fly ash activating agent is added in an amount of 1-10% of the total amount of the portland cement clinker and the fly ash.

The invention has the beneficial effects that:

1. the preparation method adopts a catalyst CuI and a cocatalyst ZrO₂The catalyst has a good catalytic effect, is easily separated from the reaction system, and can be easily activated and reused in the catalysis of the reaction. The catalyst system of the invention is very inexpensive compared to expensive noble metal catalysts and does not introduce chloride ions into the product, which is very advantageous for the use of the alkanolamine.

2. The preparation method of the invention adopts specific amine additives, can reduce the generation of colored impurities, has better effect of reducing the chromatic value of the product, and is also very helpful for promoting the complete reaction and improving the purity of the product.

3. After the preparation method is finished, the catalyst, the ethylene oxide and the mixture of the ethanolamine and the diethanolamine can be easily separated and recycled, and on one hand, the method has high atom economy; on the other hand, the difficulty of product purification is reduced, and higher-quality products are easily obtained. At the same time, the small amount of residual triethanolamine in the product does not affect the use of the alkanolamine in the present invention, which also reduces the requirement for purification of the product.

4. The invention provides a novel alkanolamine having a core of a straight-chain alkylenediamine to which are attached a plurality of 2-hydroxyethyl/hydroxy groups on each side. The alkanolamine has an effect superior to that of conventional alkanolamines such as triethanolamine, diethanol monoisopropanolamine, and the like in use.

In conclusion, the preparation method can effectively prepare the novel alkanolamine with the linear chain alkylenediamine as the core, and the product has wide application range; the yield of the reaction is high, the product purity is high, and the chromatic value is low; the preparation method has high economical efficiency, few three wastes and good environmental protection. Therefore, the method is particularly suitable for industrial application and has excellent popularization value.

Detailed Description

Hereinafter, preferred examples of the invention will be described in detail. The examples are given for the purpose of better understanding the inventive content and are not intended to be limiting. Insubstantial modifications and adaptations of the embodiments in accordance with the present disclosure remain within the scope of the invention.

Example (b):

example 1: preparation of 1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-ol

Adding 374g of liquid ammonia, 1141g of 1, 5-hexadiene diepoxide, CuI76g serving as a catalyst and ZrO serving as a cocatalyst into a reaction kettle₂25g and a small amount of hexamethylenetetramine (about 28g), then replacing the air in the solution by nitrogen, sealing the reaction kettle, heating the reaction kettle to 60 ℃, and reacting for 4 hours; and introducing ethylene oxide gas into the reactor, raising the reaction temperature to 85 ℃, maintaining the pressure in the reactor at 0.25-0.3 Mpa, and continuing to react for 5 hours. Filtering and recovering the catalyst while the catalyst is hot after the reaction is finished, rectifying the filtrate, removing low boiling point substances, gradually heating to 140-150 ℃ under the vacuum degree of 10mmHg, recovering a mixture of ethanolamine and diethanolamine, wherein the residual base solution is 3127g of a target product 1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-ol, the yield is 96.4% in terms of 1, 5-hexadiene diepoxide, and the purity is 98.8%; wherein the content of triethanolamine is 0.6%. The APHA color is less than or equal to 20.

ESI-MS：325.43[M+H]⁺

Elemental analysis (C)₁₄H₃₂N₂O₆): theoretical value: c, 51.83; h, 9.94; n,8.64, found: c, 51.94; h, 9.85; n, 8.79.

¹H NMR(400MHz,DMSO-d₆)δ4.17(b,2H),3.92(b,4H),3.65(qui,2H),3.37-3.45(m,8H),2.72-2.89(m,12H),1.41-1.57(m,4H)。

Example 2: preparation of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol

Adding 374g of liquid ammonia, 1422g of 1, 7-octadiene diepoxide, CuI76g serving as a catalyst and ZrO serving as a cocatalyst into a reaction kettle₂25g and a small amount of hexamethylenetetramine (about 28g), then replacing the air in the solution by nitrogen, sealing the reaction kettle, heating the reaction kettle to 65 ℃, and reacting for 4.5 hours; and introducing ethylene oxide gas into the reactor, raising the reaction temperature to 90 ℃, maintaining the pressure in the reactor at 0.28-0.32 Mpa, and continuing to react for 6 hours. Filtering and recovering the catalyst while the catalyst is hot after the reaction is finished, rectifying the filtrate, removing low boiling point substances, gradually heating to 140-150 ℃ under the vacuum degree of 10mmHg, recovering a mixture of ethanolamine and diethanolamine, wherein the residual base solution is a target product 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol 3344g, the yield is 94.9% in terms of 1, 7-octadiene diepoxide, and the purity is 98.4%; wherein the content of triethanolamine is 0.7%. The APHA color is less than or equal to 20.

ESI-MS：353.20[M+H]⁺

Elemental analysis (C)₁₆H₃₆N₂O₆): theoretical value: c, 54.52; h, 10.30; n,7.95, found: c, 54.41; h, 10.37; and N, 7.91.

¹H NMR(400MHz,DMSO-d₆)δ4.18(b,2H),3.93(b,4H),3.63(qui,2H),3.38-3.46(m,8H),2.70-2.86(m,12H),1.44-1.50(m,4H),1.28-1.34(m,4H)。

Example 3: preparation of 1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-ol

Adding 374g of liquid ammonia, 1141g of 1, 5-hexadiene diepoxide, CuI76g serving as a catalyst and ZrO serving as a cocatalyst into a reaction kettle₂15g and a small amount of hexamethylenetetramine (about 14g), then replacing the air in the solution by nitrogen, sealing the reaction kettle, heating the reaction kettle to 60 ℃, and reacting for 5 hours;and introducing ethylene oxide gas into the reactor, raising the reaction temperature to 85 ℃, maintaining the pressure in the reactor at 0.25-0.3 Mpa, and continuing to react for 5 hours. Filtering and recovering the catalyst while the catalyst is hot after the reaction is finished, rectifying the filtrate, removing low boiling point substances, gradually heating to 140-150 ℃ under the vacuum degree of 10mmHg, recovering a mixture of ethanolamine and diethanolamine, wherein the residual base solution is a target product 1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-alcohol 3088g, the yield is 95.2% in terms of 1, 5-hexadiene diepoxide, and the purity is 98.5%; wherein the content of triethanolamine is 0.7%. The APHA color is less than or equal to 20.

Example 4: preparation of 1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-ol

100g of the catalyst and cocatalyst mixture recovered in example 1 or 2 was added to 200ml of 5% hydrochloric acid, stirred for 15min, filtered and washed with ethanol, and then vacuum-dried. Taking 50g of the catalyst, 38g of fresh CuI catalyst and ZrO co-catalyst₂12g together were used as catalyst and the experiment of example 1 was repeated. As a result, 3072g of 1, 6-bis (2-hydroxyethyl) amino) hexane-2, 5-ol was obtained in a yield of 94.7% and a purity of 98.2% based on 1, 5-hexadiene diepoxide; wherein the content of triethanolamine is 0.8%. The APHA color is less than or equal to 20.

Comparative example 1: preparation of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol

The reaction kettle was charged with 37.4g of liquid ammonia, 142.2g of 1, 7-octadiene diepoxide, CuI7.6g of catalyst, and ZrO 2 as cocatalyst₂2.5g, then replacing air in the reaction kettle with nitrogen, sealing the reaction kettle, heating to 65 ℃, and reacting for 6 hours; and introducing ethylene oxide gas into the reactor, raising the reaction temperature to 90 ℃, maintaining the pressure in the reactor at 0.3-0.35 Mpa, and continuing to react for 6 hours. After the reaction, the catalyst was recovered by filtration while it was hot, and the filtrate was rectified to obtain 323.2g of a residual base solution, in which the content of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol was 96.0% and the content of triethanolamine was 2.1%. APHA color 75.

Comparative example 2: preparation of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol

Adding 37.4g of liquid ammonia, 142.2g of 1, 7-octadiene diepoxide, CuI11.4g of catalyst and a small amount of hexamethylenetetramine (about 2.8g) into a reaction kettle, replacing the air in the reaction kettle with nitrogen, sealing the reaction kettle, heating to 70 ℃, and reacting for 6 hours; and introducing ethylene oxide gas into the reactor, raising the reaction temperature to 90 ℃, maintaining the pressure in the reactor at 0.3-0.35 Mpa, and continuing to react for 8 hours. After the reaction, the catalyst was recovered by filtration while it was hot, and the filtrate was rectified to obtain 298.5g of a residual base solution, in which the content of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-ol was 94.7% and the content of triethanolamine was 4.2%. APHA color number 30.

The above test results demonstrate that the preparation process of the present invention can produce alkanolamines having a linear alkylenediamine core, and that the process of the present invention can obtain a high purity product in a high yield thanks to the use of a catalyst, a co-catalyst and additives.

Application example:

application example 1: mineral powder reinforcing agent

66 portions of Na₂SO₄20 portions of NaAlO₂And 14 parts of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-alcohol are uniformly mixed to obtain the mineral powder reinforcing agent.

66 portions of Na₂SO₄20 portions of NaAlO₂And 14 parts of diethanol monoisopropanolamine are uniformly mixed to obtain the contrast mineral powder reinforcing agent.

Molding, maintaining and activity testing of the mortar test piece are carried out according to a method in appendix A in granulated blast furnace slag powder for cement, mortar and concrete (GB/T18046-2017). The mineral powder is S75 mineral powder of Duchenne building materials LLC, the cement is P.O 42.5.5 Portland cement meeting GB175 regulation, and the specific surface area is 350m²In terms of/kg. In the test sample, the weight ratio of the comparative cement to the mineral powder is 1:1, and the dosage of the mineral powder reinforcing agent is 1.5% of the weight of the cementing material. The results are shown in table 1:

table 1:

application example 2: fly ash activator

And uniformly mixing 56 parts of calcium sulfate, 14 parts of potassium carbonate, 18 parts of sodium silicate and 12 parts of 1, 8-bis (2-hydroxyethyl) amino) octane-2, 7-alcohol to obtain the fly ash activator.

And uniformly mixing 56 parts of calcium sulfate, 14 parts of potassium carbonate, 18 parts of sodium silicate and 12 parts of diethanol monoisopropanolamine to obtain the comparative fly ash activator.

Molding and maintaining a mortar test piece and testing the strength activity index according to a method of appendix C in fly ash for cement and concrete (GB/T1956-2017); the stirring and water demand ratio test was performed according to the method of appendix A. The fly ash is class F II fly ash of Xiamen-HaoLian building materials Co.Ltd, the cement is P.O 42.5.5 Portland cement meeting GB175 regulation, and the specific surface area is 350m²In terms of/kg. In the test sample, the weight ratio of the comparative cement to the fly ash is 7:3, and the amount of the fly ash activator is 3% of the weight of the cementing material. The results are shown in table 2:

table 2:

finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.