A composite accelerator and preparation method thereof

Abstract

The present invention provides a composite accelerator and a preparation method thereof, wherein the composite accelerator is prepared by mixing the following components by weight: 35-45 parts of benzyl alcohol alkali steaming byproducts, 35-45 parts of alcohol amines, and 10-30 parts of polyamines; the benzyl alcohol alkali steaming byproducts are distillation residues produced in the alkali steaming process of toluene oxidation to produce benzyl alcohol, and the distillation residues are adjusted to neutral pH by acid solution, and then phase-separated and dehydrated to obtain an oil phase. The composite accelerator prepared by the present invention utilizes the benzyl alcohol alkali steaming byproducts to convert them into high value-added accelerator products, which reduces environmental pressure and reduces expenditures while increasing the output value of enterprises, and the preparation method is simple in process, easy to operate, and conducive to wide promotion and application.

Description

Technical Field

[0001] The invention belongs to the field of recycling by-products in a process of producing benzyl alcohol by oxidizing toluene, and specifically relates to a composite accelerator and a preparation method thereof. Background Art

[0002] In the process of producing benzyl alcohol by toluene liquid phase air oxidation, many side reactions occur under high temperature and high pressure conditions, resulting in many by-products in the benzyl alcohol distillation and purification process. These by-products are mainly used as low value-added fuels or landfilled, and some even need to be entrusted to solid waste treatment plants for detoxification, causing great environmental pressure and economic losses to enterprises. Therefore, how to convert the distillation by-products produced in the process of toluene oxidation to produce benzyl alcohol into high value-added products is a topic that needs to be studied urgently. Summary of the invention

[0003] In view of this, the present invention provides a composite accelerator and a preparation method thereof, which utilizes the by-product of benzyl alcohol alkali steaming to convert it into a high value-added accelerator product.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A composite accelerator is prepared by mixing the following components by weight: 35-45 parts of benzyl alcohol alkali distillation by-product, 35-45 parts of alcohol amine, and 10-30 parts of polyamine;

[0006] The benzyl alcohol alkali distillation byproduct is an oil phase obtained by adjusting the pH of the distillation residue to neutral with an acid solution, separating the residue and then dehydrating the residue to obtain an oil phase during the alkali distillation process of producing benzyl alcohol by oxidation of toluene.

[0007] Furthermore, the benzyl alcohol alkali distillation byproduct comprises the following weight fractions: 50%-65% of o-cresol, 25%-35% of p-cresol, 2%-10% of m-cresol, 2%-5% of 2-methylbiphenyl and 2%-8% of benzyl alcohol.

[0008] Furthermore, the alcoholamine is one or more of ethanolamine, diethanolamine, triethanolamine, phenylpropanolamine, and diisopropanolamine.

[0009] Furthermore, the polyamine is one or more of hexamethylenediamine, cyclohexamethylenediamine, pentamethylenediamine, methylcyclopentamethylenediamine, diethylenetriamine, triethylenetetramine, and mixed amine A1000.

[0010] A preparation method of the composite accelerator comprises the following steps: taking benzyl alcohol alkali steaming byproduct, alcohol amine and polyamine and mixing them at once, stirring them evenly and performing vacuum dehydration after reaction to obtain the composite accelerator.

[0011] Furthermore, the reaction conditions are: temperature 30-50°C, time 3-5h.

[0012] Application of the composite accelerator in the curing reaction of amine curing agent and epoxy resin.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The present invention utilizes the distillation residue generated in the alkali distillation process of toluene oxidation to produce benzyl alcohol, and compounding alcohol amine and polyamine to react to form a promoter, and converting it into a high value-added promoter product, thereby increasing the output value of the enterprise while reducing environmental pressure and expenditure;

[0015] (2) The accelerator prepared by the present invention can greatly improve the performance indicators of the cured product after the curing reaction of the amine curing agent and the epoxy resin, thereby broadening the application scenarios of the cured product;

[0016] (3) The accelerator prepared by the present invention only needs to be mixed with the byproduct of benzyl alcohol alkali distillation, alcohol amine and polyamine, and the method is simple in process and easy to operate, which is conducive to wide promotion and application. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0018] Sources and physical and chemical parameters of key test materials:

[0019] The amine curing agent is diaminodiphenylmethane curing agent (DDM), purchased from Zhangjiagang Yarui Chemical Co., Ltd., with physical and chemical parameters: amine value 540 (mg / g), viscosity 25°C ≤ 600-900 (mPa.s).

[0020] The manufacturer of epoxy resin E51 is Nan Ya in Taiwan, China. The physical and chemical parameters are: epoxy value 0.48-0.54 (eq / 100g), viscosity 25℃≤14000 (mPa.s).

[0021] The by-products of benzyl alcohol alkali steaming come from Hubei Kelin Bolun New Materials Co., Ltd. The main components of the by-products of benzyl alcohol alkali steaming include: 50%-65% of o-cresol, 25%-35% of p-cresol, 2%-10% of m-cresol, 2%-5% of 2-methylbiphenyl and 2%-8% of benzyl alcohol; when the process control fluctuates, the composition of the by-products of benzyl alcohol alkali steaming will change, such as the production of 1%-10% of benzyl formate, 10%-15% of bibenzyl, 1%-5% of dibenzyl ether, 10%-15% of biphenyl, 1%-5% of benzyl ester and other substances.

[0022] The specific raw materials not described in the present invention are all existing materials and can be directly purchased from the market.

[0023] Example 1

[0024] The present embodiment provides a method for preparing a composite accelerator, which is as follows: benzyl alcohol alkali distillation byproduct (62.80% of o-cresol, 25.98% of p-cresol, 5.96% of m-cresol, 2.12% of 2-methylbiphenyl and 2.34% of benzyl alcohol), triethanolamine and pentamethylenediamine are added to a reaction container with a stirrer in a weight ratio of 40:40:20, stirring is started, the reactor is heated to 40° C., the reaction is kept warm for 4 hours, and finally vacuum dehydration is performed until no water is distilled out to obtain the composite accelerator.

[0025] Example 2

[0026] This embodiment provides a method for preparing a composite accelerator, and the raw materials and process steps used are basically the same as those in Example 1, except that the weight ratio of the by-product of the alkali distillation of benzyl alcohol, triethanolamine, and pentamethylenediamine is 50:30:20.

[0027] Example 3

[0028] This embodiment provides a method for preparing a composite accelerator. The raw materials and process steps used are basically the same as those in Example 1, except that the weight ratio of the by-product of the alkali distillation of benzyl alcohol, triethanolamine, and pentamethylenediamine is 34:33:33.

[0029] Example 4

[0030] The present embodiment provides a method for preparing a composite accelerator. The raw materials and process steps used are basically the same as those in Example 1, except that: the process control fluctuates. At this time, the main components of the by-product of alkali distillation of benzyl alcohol are 40.88% of o-cresol, 19.54% of p-cresol, 4.82% of m-cresol, 14.32% of biphenyl, 13.18% of bibenzyl, 4.89% of dibenzyl ether and 2.11% of benzyl alcohol.

[0031] Example 5

[0032] The present embodiment provides a preparation method for a composite accelerator. The raw materials and process steps used are basically the same as those in Example 1, except that: the process control fluctuates. At this time, the main components of the by-product of the alkali distillation of benzyl alcohol are 7.53% of benzyl formate, 44.26% of o-cresol, 13.29% of p-cresol, 4.17% of m-cresol, 6.75% of biphenyl, 12.87% of bibenzyl, 4.69% of benzyl ester and 4.58% of benzyl alcohol.

[0033] Example 6

[0034] This embodiment provides a method for preparing a composite accelerator, and the raw materials and process steps used are basically the same as those of Example 1, except that an equal amount of diisopropanolamine is used instead of triethanolamine.

[0035] Example 7

[0036] This embodiment provides a method for preparing a composite accelerator, and the raw materials and process steps used are basically the same as those of Example 1, except that an equal amount of diethanolamine is used instead of triethanolamine.

[0037] Example 8

[0038] This embodiment provides a method for preparing a composite accelerator, and the raw materials and process steps used are basically the same as those of Example 1, except that an equal amount of hexamethylenediamine is used instead of pentamethylenediamine.

[0039] Example 9

[0040] This embodiment provides a method for preparing a composite accelerator. This embodiment provides a method for preparing inorganic binder coated sand. The raw materials and process steps used are basically the same as those in Example 1, except that an equal amount of diethylenetriamine is used instead of pentamethylenediamine.

[0041] Example 10

[0042] This embodiment provides a method for preparing a composite accelerator, and the raw materials and process steps used are basically the same as those of Example 1, except that an equal amount of mixed amine Amix 1000 is used to replace pentamethylenediamine.

[0043] The accelerators prepared in Examples 1-10 were respectively added to the diaminodiphenylmethane curing agent system, and the added amount accounted for 5 parts of the curing agent system. The curing agent with the accelerator was then mixed with the epoxy resin E51 in the same proportion to undergo a curing reaction, and various indicators of the cured product after the reaction were measured. The control group was a curing reaction of the curing agent without the addition of the accelerator and the epoxy resin E51.

[0044] The specific detection methods are as follows:

[0045] Accelerator viscosity: measured using GB / T22314-2008 method.

[0046] Shore hardness: measured using GB / T2411-2008 method.

[0047] Tensile strength: measured using GB / T2567-2021 method.

[0048] Shear strength: measured using the GB / T2567-2021 method.

[0049] Compressive strength: measured using GB / T2567-2021 method.

[0050] Bending strength: measured using GB / T2567-2021 method.

[0051] Table 1 Performance indicators of the cured product after the control group and the curing reaction after adding the accelerator

[0052]

[0053] From Table 1, we can see that:

[0054] Compared with the control group, except for the longer curing gel time of Example 2, Example 4 and Example 5 than the control group, the other examples can accelerate the gel time of the curing system. Compared with the control group, the performance of the cured product in each example is greatly improved except for Example 4 which is not significantly improved. After adding the composite accelerator in Example 1, the gel time is fast and the performance of the cured product is excellent, which is the best composite accelerator ratio.

[0055] Compared with Examples 1-3, it can be seen that the weight ratio of the benzyl alcohol alkali steam byproduct, triethanolamine, and pentamethylenediamine has a certain influence on the performance of the cured product. When the ratio of the three is 40:40:20, the gel time of the curing reaction is the fastest, and the addition of the accelerator has little effect on the performance of the cured product. This ratio has the best effect.

[0056] Compared with Examples 1, 4, and 5, it can be seen that when the operating process is changed to cause the composition of the benzyl alcohol alkali evaporation by-product to change, the prepared accelerator has a significant effect on the speed of the curing reaction, and the performance of the cured product after curing is significantly reduced; when the composition of the benzyl alcohol alkali evaporation by-product is in the range of 50%-65% of o-cresol, 25%-35% of p-cresol, 2%-10% of m-cresol, 2%-5% of 2-methylbiphenyl, and 2%-8% of benzyl alcohol, the promotion effect is good and the effect on the performance of the cured product after curing is small.

[0057] Compared with Examples 1, 6 and 7, it can be seen that the environmentally friendly accelerator prepared using triethanolamine has the shortest gel time and the application performance of the cured product is more excellent.

[0058] Comparison of Examples 1, 8, 9, and 10 shows that the change in the type of polyamine has a relatively excellent effect on the performance of the cured product.

[0059] In summary, the addition of the accelerator prepared according to the present invention can greatly improve the performance indicators of the cured product after the amine curing agent and the epoxy resin are cured, and the generated by-products are converted into high-value-added accelerator products, which can increase the output value of the enterprise while reducing environmental pressure and reducing expenses. In addition, the preparation is simple, which is conducive to large-scale promotion and application.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite accelerator, characterized in that: The method comprises mixing the following groups of parts by weight: 35-45 parts of benzyl alcohol alkali distillation byproduct, 35-45 parts of alcohol amine, and 10-30 parts of polyamine; The benzyl alcohol alkali distillation byproduct is an oil phase obtained by adjusting the pH of the distillation residue to neutral with acid solution, then separating the phases and performing dehydration treatment on the distillation residue produced in the alkali distillation process of producing benzyl alcohol by oxidation of toluene; The benzyl alcohol alkali distillation byproduct comprises the following components by weight: 50%-65% of o-cresol, 25%-35% of p-cresol, 2%-10% of m-cresol, 2%-5% of 2-methylbiphenyl and 2%-8% of benzyl alcohol; The alcoholamine is one or more of ethanolamine, diethanolamine, triethanolamine, phenylpropanolamine, and diisopropanolamine; The polyamine is one or more of hexamethylenediamine, cyclohexamethylenediamine, pentamethylenediamine, methylcyclopentamethylenediamine, diethylenetriamine, triethylenetetramine, and Amix1000.

2. The composite accelerator according to claim 1, characterized in that The method comprises mixing the following groups of parts by weight: 38-42 parts of benzyl alcohol alkali distillation by-product, 38-42 parts of alcohol amine, and 18-22 parts of polyamine.

3. The composite accelerator according to claim 1, characterized in that The method comprises mixing the following groups of parts by weight: 40 parts of benzyl alcohol alkali distillation by-product, 40 parts of alcohol amine and 20 parts of polyamine.

4. A method for preparing the composite accelerator according to any one of claims 1 to 3, characterized in that: The following steps are involved: The byproduct of alkali distillation of benzyl alcohol, alcohol amine and polyamine are mixed at once, stirred evenly and vacuum dehydrated to obtain a composite accelerator.

5. The preparation method according to claim 4, characterized in that: The reaction conditions are: temperature 30-50°C, time 3-5h.

6. Use of the composite accelerator according to any one of claims 1 to 3 in the curing reaction of an amine curing agent and an epoxy resin.

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