阅读说明：本技术 一种临氢催化胺化制备端氨基聚醚多元醇的合成方法 (Synthetic method for preparing amino-terminated polyether polyol through hydrogen catalytic amination ) 是由 王国强 见方田 周国栋 于 2020-12-04 设计创作，主要内容包括：本发明属于化工合成技术领域,具体涉及一种临氢催化胺化制备端氨基聚醚多元醇的合成方法,先用聚醚与丙烯腈在强碱性条件下生成聚醚腈,再将聚醚腈在液氨条件下用负载镍催化剂及改性助剂与氢气发生还原反应制备端氨基聚醚多元醇,最后通过减压蒸馏法分离产物。与现有直接胺化技术相比,本发明原料转化率高,胺化产品收率97％以上,由于改性助剂的使用,可有效降低仲胺及高聚物副产物小于3％,后续产品分离简单,无需循环回用未反应的原料与中间体,降低能耗,最终降低生产成本。(The invention belongs to the technical field of chemical synthesis, and particularly relates to a synthesis method for preparing amino-terminated polyether polyol through hydrogen catalytic amination. Compared with the prior direct amination technology, the invention has high conversion rate of raw materials, the yield of aminated products is more than 97%, secondary amine and high polymer byproducts can be effectively reduced by less than 3% due to the use of the modification auxiliary agent, the subsequent products are simple to separate, unreacted raw materials and intermediates are not required to be recycled, the energy consumption is reduced, and the production cost is finally reduced.)

1. A synthetic method for preparing amino-terminated polyether polyol by hydrogen catalytic amination is characterized by comprising the following steps: polyether nitrile is firstly generated by polyether and acrylonitrile under strong alkaline condition, then the polyether nitrile is subjected to reduction reaction with hydrogen by using a supported nickel catalyst and a modification auxiliary agent under liquid ammonia condition to prepare the amino-terminated polyether polyol, and finally the product is separated by a reduced pressure distillation method.

2. The method of claim 1 for preparing amine-terminated polyether polyol by hydrocatalytic amination, which is characterized in that: the molar ratio of the polyether to the acrylonitrile is 1: 2.

3. the method of claim 1 for preparing amine-terminated polyether polyol by hydrocatalytic amination, which is characterized in that: the strong alkaline condition is provided by KOH solution with the concentration of 40 weight percent, and the KOH solution accounts for 0.1 to 10 percent of the mass of the polyether.

4. The method of claim 1 for preparing amine-terminated polyether polyol by hydrocatalytic amination, which is characterized in that: the reaction conditions of the polyether and acrylonitrile for generating polyether nitrile under the strong alkaline condition are that the reaction temperature is 80 ℃ and the pressure is 4.0 MPa.

5. The method of claim 1 for preparing amine-terminated polyether polyol by hydrocatalytic amination, which is characterized in that: the dosage of the supported nickel catalyst is 25-45% of the mass of the polyether, the dosage of the modification auxiliary agent is 3-25% of the mass of the total system of the reduction reaction, and the molar ratio of the hydrogen to the polyether nitrile is 4: 1.

6. The process according to claim 1 or 5, wherein the hydrogenation is catalyzed and aminated to prepare amine-terminated polyether polyol: the supported nickel catalyst comprises an active component nickel and a carrier, wherein the content of the active component nickel is 0.5-10% based on the total weight of the supported nickel catalyst, the carrier is silicon oxide, aluminum oxide or titanium oxide, and the content of the carrier is 1-50%.

7. The process according to claim 1 or 5, wherein the hydrogenation is catalyzed and aminated to prepare amine-terminated polyether polyol: the modifying assistant is one or more of sodium hydroxide, potassium hydroxide or cesium hydroxide, and is added in the form of aqueous solution with the concentration of 1-60 wt%.

8. The method of claim 1 for preparing amine-terminated polyether polyol by hydrocatalytic amination, which is characterized in that: the reaction temperature of the reduction reaction is 90-200 ℃, and the pressure is 4.0-8.0 MPa.

9. The method of claim 1 for preparing amine-terminated polyether polyol by hydrocatalytic amination, which is characterized in that: the boiling range of the distillation is 160-170 ℃.

Technical Field

The invention belongs to the technical field of chemical synthesis, and particularly relates to a synthesis method for preparing amino-terminated polyether polyol by hydrogen catalytic amination.

Background

Amino-terminated polyether polyols (i.e., polyetheramines) are a class of compounds that are used primarily for spray polyurea elastomers, RIM (reaction injection molded) products, epoxy curing agents, and motor fuel oil additives. The polyurea elastomer prepared from the amino-terminated polyether polyol has high strength, high elongation, abrasion resistance, corrosion resistance and aging resistance, is widely applied to waterproof, anticorrosive and wear-resistant coatings on the surfaces of concrete and steel structures and protective and decorative coatings of other members, and is a high-performance polyurethane elastomer. The key technology is the synthesis of amino-terminated polyether polyol.

The amino-terminated polyether polyol is also widely used as an epoxy resin curing agent, can improve the toughness of products, and is widely used for manufacturing ring resin artware. The amino-terminated polyether polyol is a novel material which has just emerged in the last 90 th century, is a curing agent for epoxy resin, and the resin cured by the amino-terminated polyether polyol has excellent toughness, impact resistance and low temperature resistance. Because the product has low color value, the solidified plain casting body is glittering and translucent. It is also an additive of engine fuel oil, and has the function of anti-deposition, and is also an additive component of lubricating grease, and is favorable for raising wear resistance of machine parts. In addition, the amino-terminated polyether polyols are also widely used in the fields of surfactants, water-soluble coatings and adhesives. The synthesis of amino-terminated polyether polyols is very versatile. The main method comprises the following steps: hydrolysis, aminophenoxy, ammonolysis, leaving group, etc. The industrial production of amino polyether mainly adopts high-pressure reductive amination. Currently, there are two main research ideas about the synthesis method of amino-terminated polyether polyol (ATPE):

1) catalytic reductive amination: starting from the terminal hydroxyl group of polyether polyol, ammonia (amino replaces the terminal hydroxyl group) is used for ammonolysis reaction, which is also the main method for industrially synthesizing the prior terminal amino polyether polyol (ATPE). the industrial production of the ATPE at home and abroad mainly adopts a high-pressure reductive amination method, and no enterprise is produced at home.

2) Leaving group method: the method is generally divided into two steps, wherein the first step is esterification reaction, starting from active hydrogen of hydroxyl at the tail end of polyether polyol, a compound (p-toluenesulfonic acid vinyl, acyl chloride, halogen, carboxyl, aldehyde group and the like) with an easy-to-leave group or an unsaturated group is used for carrying out end capping with the active hydrogen, and the second step is amination reaction, and a product obtained in the first step is reacted with amine (mono-amine or polyamine to obtain ATPE).

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a synthesis method for preparing amino-terminated polyether polyol by hydrogen catalytic amination, which has the advantages of high conversion rate of raw materials, low content of byproducts, simple product separation, no need of recycling unreacted raw materials and intermediates, reduced energy consumption and finally reduced production cost.

The invention relates to a synthesis method for preparing amino-terminated polyether polyol by hydrogen catalytic amination, which is characterized by comprising the following steps: polyether nitrile is firstly generated by polyether and acrylonitrile under strong alkaline conditions, then the polyether nitrile is subjected to reduction reaction with hydrogen under the condition of liquid ammonia by using a supported nickel catalyst and a modification auxiliary agent to prepare the amino-terminated polyether polyol, and because a plurality of side reactions are generated while the amino-terminated polyether polyol is prepared, and finally the product is separated by a reduced pressure distillation method, the satisfactory yield of the amino-terminated polyether polyol is achieved.

In the invention, the polyether is conventional polyether polyol sold in the market, or is a polymer prepared by performing addition polymerization reaction on organic amine serving as an initiator and Propylene Oxide (PO), Ethylene Oxide (EO) and the like in the presence of a catalyst. The present invention does not limit the kind or chemical structure of the polyether.

In the invention, the added liquid ammonia is used for ensuring that the primary amine with high yield is obtained, the most effective method is to reduce the nitrile in the presence of the liquid ammonia, and the method using the liquid ammonia as an auxiliary agent is a good method for preventing the generation of secondary amine.

Further, the molar ratio of the polyether to acrylonitrile is 1: 2.

further, the strongly basic condition is provided by a 40 wt% strength KOH solution. The KOH solution accounts for 0.1 to 10 percent of the mass of the polyether, and preferably 0.5 to 3 percent. The strong alkaline condition can reduce the byproducts generated by the reaction of the polyether and the acrylonitrile (mainly the generation of nitrile alcohol and the self polymerization of the acrylonitrile), and ensure the selectivity of the polyether nitrile main product.

The reaction conditions of the polyether and acrylonitrile for generating polyether nitrile under the strong alkaline condition are that the reaction temperature is 80 ℃ and the pressure is 4.0 MPa.

Furthermore, the dosage of the supported nickel catalyst is 25-45% of the mass of the polyether, preferably 30%, the dosage of the modification auxiliary agent is 3-25% of the mass of the total reduction reaction system, preferably 3-10%, more preferably 3-5%, and the molar ratio of the hydrogen to the polyether nitrile is 4: 1.

Further, the supported nickel catalyst comprises an active component nickel (Ni), a carrier and an optional auxiliary agent. Based on the total weight of the supported nickel catalyst, the content of the active component nickel is 0.5-10%, preferably 1-5%, the carrier is silicon oxide, aluminum oxide or titanium oxide, and the content of the carrier is 1-50%. In the research process of applying the catalyst system to hydrogenation reduction reaction, the active metal component Ni shows excellent activity to polyether nitrile hydrogenation reduction reaction, particularly performs hydrogenation reduction on a high-purity product of polyether nitrile as a reaction body, and obviously improves the reaction activity of unit catalyst mass, the selectivity to a target amination product and the conversion rate of raw materials compared with the conventional amination catalyst with high metal content such as Cr. But when the content of the introduced Ni in the catalyst is less than 0.5 percent, the selectivity of the catalyst is obviously reduced in the hydrogenation catalysis process; when the Ni content is more than 10%, the increase of the Ni content does not contribute to the improvement of the activity and selectivity of the catalyst, and even by-products are increased, so that the Ni content in the catalyst is controlled to be 0.5 to 10%, preferably 1 to 5%. The addition of the auxiliary agent is used for improving the toxicity resistance and carbon deposition resistance of the catalyst and prolonging the service life of the catalyst, for example, 0.5-2% of a compound auxiliary agent of Mn and Ce (the compound mass ratio is 5:1-1:5) is added.

The preparation method of the catalyst adopts an impregnation method well known in the industry, and uses metal solution to impregnate the carrier to obtain a catalyst precursor; and drying and roasting the catalyst precursor to obtain the catalyst.

Furthermore, the modification auxiliary agent is one or more of sodium hydroxide, potassium hydroxide or cesium hydroxide, and is added in the form of aqueous solution, wherein the concentration of the modification auxiliary agent is 1-60 wt%, and preferably 5-15 wt%. The modified auxiliary agent can improve the catalytic surface polymerization phenomenon, reduce the generation of secondary amine byproducts and high polymers in the reaction process, and improve the selectivity of primary amination products.

Further, the reaction temperature of the reduction reaction is 90-200 ℃, preferably 100-150 ℃, and the pressure is 4.0-8.0MPa, preferably 4.0-5.0 MPa. In the invention, the reduction reaction can be carried out intermittently or continuously, preferably intermittently, the intermittent use saves the utilization cost of reactants, reduces the discharge amount of three wastes, and has simple process flow, simple and convenient operation, mature technology and full attention to the advancement of the technology. The batchwise preparation of the amino-terminated polyether polyols can be carried out in the tubular reactor in the liquid-phase or gas-phase reaction. In the present invention, a solvent may or may not be used in the reduction process, and the solvent includes, but is not limited to, liquid ammonia, benzene, toluene, and ethanol, and the present invention is preferably performed under the condition of using a solvent.

Further, the boiling range of the distillation is 160-170 ℃, preferably 164-167 ℃.

The invention has the advantages that: compared with the prior direct amination technology, the invention has high conversion rate of raw materials, the yield of aminated products is more than 97%, secondary amine and high polymer byproducts can be effectively reduced by less than 3% due to the use of the modification auxiliary agent, the subsequent products are simple to separate, unreacted raw materials and intermediates are not required to be recycled, the energy consumption is reduced, and the production cost is finally reduced.

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited to the examples listed, and it should also include equivalent modifications and variations to the technical solutions defined in the claims appended to the present application.

Example 1:

a synthetic method for preparing amino-terminated polyether polyol by hydrogen catalytic amination comprises the steps of firstly adding polyether, acrylonitrile and a KOH solution with the concentration of 40 wt% into a reaction kettle in sequence, wherein the molar ratio of the polyether to the acrylonitrile is 1: 2, the KOH solution accounts for 2 percent of the mass of the polyether, the temperature is raised to 80 ℃, the pressure is 4Mpa, the polyether nitrile intermediate is prepared, and the high-purity polyether nitrile is prepared for subsequent use by a reduced pressure distillation method due to the existence of byproducts such as nitrile alcohol, acrylonitrile and the like.

Adding polyether nitrile into an amination reaction kettle, adding a nickel-loaded catalyst and a modification auxiliary agent in advance, and adding liquid ammoniaAnd introducing hydrogen, wherein the dosage of the supported nickel catalyst is 30% of the mass of the polyether, the dosage of the modification auxiliary agent is 5% of the mass of the total reduction reaction system, and the molar ratio of the hydrogen to the polyether nitrile is 4: 1. Reacting for 24 hours at 120 ℃ and under the pressure of 8Mpa, then sending into a degassing kettle for degassing and dehydrating, and finally filtering out impurities by a filter screen to obtain a finished product. Degassing and dewatering in a dewatering kettle (degassing kettle), heating the degassing kettle with steam to remove H in the material₂And NH₃(ii) a Finally, separating the amino-terminated polyether polyol by a distillation method, wherein the boiling range is 164-.

In this embodiment, the supported nickel catalyst includes an active component nickel (Ni), a support, and an optional auxiliary agent. Based on the total weight of the supported nickel catalyst, the content of the active component nickel is 5%, the carrier is alumina, and the content of the carrier is 50%. 2% of a compound auxiliary agent of Mn and Ce (the compound mass ratio is 5:1-1:5) can be added into the auxiliary agent.

In the embodiment, the modifying assistant is an aqueous solution of potassium hydroxide with the concentration of 10 wt%

The quality indexes of the amino-terminated polyether polyol product prepared in this example are shown in the following table:

detecting items	Index (I)	The result of the detection
			Appearance of the product	Transparent liquid	Transparent liquid
Color value (APHA)	≤25	10
			Moisture (%)	≤0.25	0.12
Total amine value (meq/g)	8.1-8.7	8.39
			Primary amine ratio (%)	≥97	99.0

The product in the embodiment passes the sampling inspection of applicant company and the inspection of quality supervision inspection of Zibo city technology, and all technical indexes of the product are qualified.

Comparative example 2:

the KOH solution concentration used in the preparation of polyether nitrile was changed to 30% by weight, as in example 1. The primary amine content of the final product was 96.4%.

Comparative example 3:

the KOH solution concentration used in the preparation of polyether nitrile was changed to 50% by weight, as in example 1. The primary amine content of the final product was 97.0%.

Comparative example 4:

the reaction temperature in the preparation of polyether nitrile was changed to 70 ℃ as in example 1. The primary amine content of the final product was 97.3%.

Comparative example 5:

the reaction temperature in the preparation of polyether nitrile was changed to 90 ℃ as in example 1. The primary amine ratio of the final product was 96.5%.

Comparative example 6:

the reaction pressure in the preparation of polyether nitrile was changed to 5MPa, as in example 1. The primary amine content of the final product was 98.1%.

Comparative example 7:

the procedure of example 1 was repeated except that no liquid ammonia was added during the reduction reaction. The primary amine ratio of the final product was 92.3%.

Comparative example 8:

the reduction was carried out in a molar ratio of hydrogen to polyether nitrile of 5:1, as in example 1. The primary amine ratio of the final product was 99.0%.

In summary, it was found from comparative examples 2 to 6 that the yield of the final amino-terminated polyether polyol product was influenced by varying the KOH solution concentration, the temperature and the pressure for preparing the polyether nitrile. Thus, the yield of the second stage polyetheramine is affected by affecting the concentration of the polyether nitrile intermediate. From comparative example 7, it was found that the absence of added liquid ammonia greatly reduced the product yield, producing a large amount of secondary amine product. From comparative example 8, it was found that the addition of excessive hydrogen did not increase the yield, and thus excessive waste was generated.