Synthetic method of odorless cationic etherifying agent

Abstract

The invention provides a synthetic method of an odorless cationic etherifying agent, which comprises the following steps: adding hydrochloric acid into a reaction kettle, slowly introducing trimethylamine, and reacting to obtain trimethylamine hydrochloride; slowly adding epichlorohydrin into the reaction kettle, and continuously reacting under the catalytic action of the acid catalyst; after dropwise adding the epoxy chloropropane, sequentially adding organic amine and an alkylating reagent for continuous reaction, and performing post-treatment on a product to obtain the odorless cationic etherifying agent. According to the invention, the odorless cationic etherifying agent is synthesized by adding the organic amine and the alkylation reagent, the product has the advantages of less free amine, less generation of organic by-products, no ammoniacal odor, no need of large-scale transformation of the existing production process and equipment, small production investment and easiness in industrialization.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of cationic etherifying agents, in particular to a method for synthesizing an odorless cationic etherifying agent. Background Art

[0002] Cationic etherifying agents are widely used in the field of fine chemicals and are multifunctional chemical products. There are two types of commercial products, one is solid and the other is aqueous solution. The aqueous solution is a colorless transparent liquid, and most of them are 69% aqueous solution at room temperature. The product can be quickly converted into an epoxidized structure with high reaction activity under alkaline conditions, so that it is easy to react chemically with compounds containing active hydrogen to obtain multifunctional chemicals containing quaternary ammonium groups.

[0003] Cationic etherifying agents are widely used in the fields of papermaking industry, daily chemical industry, petroleum industry, water treatment industry, etc. This product is used as an etherifying agent for cationic starch, cationic polysaccharide, modified guar gum, etc. It is used to prepare cationic starch, cationic polyacrylamide, electroplating additives, textile printing and dyeing auxiliaries, antistatic agents and papermaking auxiliaries, etc. It can also be used as a cationic surfactant, water treatment flocculant, textile, conductive coating, electroplating, cosmetics and other industries.

[0004] In the prior art, Chinese patents CN107353213 A, CN107349869 A, CN205556516 U, etc. are all synthesized in a kettle reactor, and go through a series of process steps such as preparation of trimethylamine hydrochloride, low-temperature dropwise addition of epichlorohydrin, room-temperature reaction, product refining, etc. Although the process is mature, the product has the defect of a strong ammonia smell, and the application range of the product cannot be expanded.

[0005] Therefore, it is necessary to develop a synthesis method of an odorless cationic etherifying agent to further improve product quality. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for synthesizing an odorless cationic etherifying agent, reduce the content of free amines, and produce less organic by-products, thereby solving the above technical problems existing in the prior art.

[0007] The present invention is achieved by adopting the following technical solutions:

[0008] A method for synthesizing an odorless cationic etherifying agent comprises the following steps:

[0009] S1, adding hydrochloric acid into a reactor, slowly introducing trimethylamine, and reacting to obtain trimethylamine hydrochloride;

[0010] S2, slowly adding epichlorohydrin into the above-mentioned reactor, and continuing the reaction under the catalytic action of the acidic catalyst;

[0011] S3. After the epichlorohydrin is added dropwise, an organic amine and an alkylating agent are added in sequence to continue the reaction, and the product is post-treated to obtain the odorless cationic etherifying agent.

[0012] In the above synthesis steps, trimethylamine, hydrochloric acid and epichlorohydrin can be added in a stoichiometric ratio. In order to make trimethylamine react completely and reduce residue, hydrochloric acid and epichlorohydrin can be appropriately excessive. Preferably, the molar ratio of trimethylamine, hydrochloric acid and epichlorohydrin is 1: (1-1.1): (1.05-1.3).

[0013] The inventors have found that, in the conventional process, i.e., first preparing trimethylamine hydrochloride, and then reacting it with epichlorohydrin under the action of an acidic catalyst to prepare a cationic etherifying agent, adding an organic amine and an alkylating agent in sequence can unexpectedly greatly reduce organic impurities and trimethylamine hydrochloride residues. Based on the above findings, the inventors have completed the present invention.

[0014] The acid catalyst is selected from at least one of dilute hydrochloric acid, dilute sulfuric acid and dilute nitric acid; the amount of the acid catalyst added is 0.9-1.3% of the total mass of trimethylamine, hydrochloric acid and epichlorohydrin.

[0015] In step S1, the trimethylamine should be completely introduced within 2-4 hours, and the reaction temperature is 20-50° C. After all the trimethylamine is added to the reactor, the reaction is continued for 0.5-1.5 hours.

[0016] In step S2, the temperature of the reactor is maintained at 5-15° C. during the addition of epichlorohydrin. Epichlorohydrin should be added slowly over a period of 4-8 hours, preferably 6-7 hours. The acidic catalyst is preferably added after 20-40% of the epichlorohydrin is added. The acidic catalyst can be added all at once or slowly added simultaneously with the remaining epichlorohydrin.

[0017] The organic amine is at least one of dimethylamine and diethylamine. The amount of the organic amine added is 1-30% of the molar amount of trimethylamine.

[0018] The alkylating agent is at least one of dimethyl carbonate and dimethyl sulfate.

[0019] The amount of the alkylating agent used is 1.05-1.20 times the molar amount of the organic amine used.

[0020] In step S3, after the organic amine is added into the reaction kettle, the temperature is raised to 35-45° C., the alkylating agent is added, and the temperature is maintained to continue the reaction for 3-5 hours.

[0021] The tasteless cationic etherifying agent of the invention is a colorless transparent liquid with an effective content of ≥69%; a pH value between 4 and 7; an epichlorohydrin residue of ≤5ppm; a 1,3-dichloropropanol content of ≤10ppm, and a product yield of greater than 98%.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The product synthesized by the traditional autoclave process has a strong ammonia smell itself and in the subsequent use process, which makes the application environment poor, unfriendly to the operators and cannot expand the application range of the product. Based on the above reasons, the present invention adds secondary ammonia and alkylating agents with less odor during the reaction process to reduce the content of free amines. Through technical optimization, an odorless cationic etherifying agent product can be obtained without large-scale transformation of the existing production process and equipment, with low production investment and easy industrialization.

[0024] (2) The present invention has good compatibility with existing traditional kettle-type equipment and does not require large-scale transformation of production equipment.

[0025] (3) The crude product prepared has less free amine, less organic by-products, and no ammonia smell. DETAILED DESCRIPTION

[0026] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only used as examples, but are not used to limit the scope of the present invention. Those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0027] The instruments or raw materials in the present invention without indicating the manufacturer are all conventional commercial instruments or raw materials.

[0028] Unless otherwise mentioned, the detection indicators involved in the embodiments of the present invention are detected by conventional detection methods in the art.

[0029] Example 1

[0030] (1) Clean the reaction device to ensure that it meets production requirements.

[0031] (2) 354 kg of 31% hydrochloric acid was pumped into the reactor, stirring was started, and 178 kg of trimethylamine was slowly introduced over 3 hours, and the temperature was maintained at 20° C. During the reaction, when all the trimethylamine was added to the reactor, the reaction was continued at room temperature for 30 minutes.

[0032] (3) The material is kept at 5°C, the metering pump is turned on, and 293 kg of epichlorohydrin is added dropwise to the reactor within 6 hours. Two hours after the start of the dropwise addition, 0.9% of the total mass of the raw material is added with dilute hydrochloric acid, an acidic catalyst, and the pH is adjusted to 9 to keep the material in a rapid reaction environment.

[0033] (4) After the epichlorohydrin addition was completed, 14.6 kg of diethylamine aqueous solution (30%) was added dropwise to the reactor within 30 minutes.

[0034] (5) Raise the temperature to 40°C, add 8.4 kg of dimethyl sulfate at one time, and maintain the temperature to continue the reaction for 2 hours.

[0035] (6) The material is transferred to the stripping device to refine the crude product.

[0036] (7) The refined product is transferred to the adjustment kettle to adjust the material content to ≥69% and pH=6.

[0037] (8) The material is cooled and discharged.

[0038] Example 2

[0039] (1) Clean the reaction device to ensure that it meets production requirements.

[0040] (2) 372 kg of 31% hydrochloric acid was pumped into the reactor, stirring was started, and 178 kg of trimethylamine was slowly introduced over 3 hours, and the temperature was maintained at 30° C. During the reaction, when all the trimethylamine was added to the reactor, the reaction was continued at room temperature for 60 minutes.

[0041] (3) The material is kept at 10°C, the metering pump is turned on, and 345 kg of epichlorohydrin is added dropwise to the reactor within 6 hours. Two hours after the start of the dropwise addition, 1.2% of the total mass of the raw material is added with dilute hydrochloric acid, an acidic catalyst, and the pH is adjusted to 9 to keep the material in a rapid reaction environment.

[0042] (4) After the epichlorohydrin was added dropwise, 50.7 kg of dimethylamine aqueous solution (40%) was added dropwise to the reactor within 30 minutes.

[0043] (5) Raise the temperature to 40°C, add 43.8 kg of dimethyl carbonate at one time, and maintain the temperature to continue the reaction for 3 hours.

[0044] (6) The material is transferred to the stripping device to refine the crude product.

[0045] (7) The refined product is transferred to the adjustment kettle to adjust the material content to ≥69% and pH=6.

[0046] (8) The material is cooled and discharged.

[0047] Example 3

[0048] (1) Clean the reaction device to ensure that it meets production requirements.

[0049] (2) 389 kg of 31% hydrochloric acid was pumped into the reactor, stirring was started, and 178 kg of trimethylamine was slowly introduced over 3 hours, and the temperature was maintained at 50° C. During the reaction, when all the trimethylamine was added to the reactor, the reaction was continued at room temperature for 90 minutes.

[0050] (3) The material is kept at 15°C, the metering pump is turned on, and 360 kg of epichlorohydrin is added dropwise to the reactor within 6 hours. Two hours after the start of the dropwise addition, 1.3% of the total mass of the raw material is added with dilute hydrochloric acid, an acidic catalyst, and the pH is adjusted to 9 to keep the material in a rapid reaction environment.

[0051] (4) After the dropwise addition of epichlorohydrin was completed, a mixture of 10.7 kg of diethylamine and 67.6 kg of a dimethylamine aqueous solution (40%) was added dropwise to the reactor within 30 minutes.

[0052] (5) Raise the temperature to 40°C, add 68.9 kg of dimethyl carbonate at one time, and maintain the temperature to continue the reaction for 4 hours.

[0053] (6) The material is transferred to the stripping device to refine the crude product.

[0054] (7) The refined product is transferred to the adjustment kettle to adjust the material content to ≥69% and pH=6.

[0055] (8) The material is cooled and discharged.

[0056] Example 4

[0057] (1) Clean the reaction device to ensure that it meets production requirements.

[0058] (2) 372 kg of 31% hydrochloric acid was pumped into the reactor, stirring was started, and 178 kg of trimethylamine was slowly introduced over 3 hours, and the temperature was maintained at 40° C. During the reaction, when all the trimethylamine was added to the reactor, the reaction was continued at room temperature for 60 minutes.

[0059] (3) The material is kept at 10°C, the metering pump is turned on, and 345 kg of epichlorohydrin is added dropwise to the reactor within 6 hours. Two hours after the start of the dropwise addition, 1.1% of the total mass of the raw material is added as an acidic catalyst, dilute hydrochloric acid, and the pH is adjusted to 9 to keep the material in a rapid reaction environment.

[0060] (4) After the epichlorohydrin was added dropwise, 50.7 kg of a dimethylamine aqueous solution (40%) was added dropwise to the reactor within 30 minutes.

[0061] (5) The temperature was raised to 40°C, 37.2 kg of dimethyl carbonate and 8.6 kg of dimethyl sulfate were added at once, and the temperature was maintained to continue the reaction for 4 hours.

[0062] (6) The material is transferred to the stripping device to refine the crude product.

[0063] (7) The refined product is transferred to the adjustment kettle to adjust the material content to ≥69% and pH=6.

[0064] (8) The material is cooled and discharged.

[0065] Comparative Example

[0066] (1) Clean the reaction device to ensure that it meets production requirements.

[0067] (2) 372 kg of 31% synthetic hydrochloric acid was pumped into the reactor, stirring was started, and 178 kg of trimethylamine was slowly introduced over 3 hours, and the temperature was maintained at 40° C. During the reaction, when all the trimethylamine was added to the reactor, the reaction was continued at room temperature for 60 minutes.

[0068] (3) The material is kept at 15°C, the metering pump is turned on, and 345 kg of epichlorohydrin is added dropwise to the reactor within 4 hours. Two hours after the start of the dropwise addition, 1.2% of the total mass of the raw material is added with dilute hydrochloric acid, an acidic catalyst, and the pH is adjusted to 9 to keep the material in a rapid reaction environment.

[0069] (4) After the addition of epichlorohydrin was completed, the temperature was raised to 40°C and the reaction was continued at this temperature for 3 hours.

[0070] (5) The material is transferred to the stripping device to refine the crude product.

[0071] (6) The refined product is transferred to the adjustment kettle to adjust the material content to ≥69% and pH=6.

[0072] (7) The material is cooled and discharged.

[0073] The following tests were performed on each embodiment and comparative example sample:

[0074] 1. Effective content detection: The effective content is detected by hydrochloric acid back titration method.

[0075] 2. Detection of organic impurity content: Detection is carried out by gas chromatography.

[0076] 3. Detection of trimethylamine hydrochloride residue: Detection is carried out by gas chromatography.

[0077] 4. Detection of diammonium salt content: Detection is carried out through ion chromatography.

[0078] 5. pH value detection: Use Leiji PHS-2F pH meter. The test results are shown in Table 1.

[0079] Table 1 Sample test data

[0080]

[0081]

[0082] It can be seen from the test results that, compared with the traditional reaction process, the cationic etherifying agent product obtained by the method of the present invention has a low total content of organic impurities and a significantly reduced amount of trimethylamine hydrochloride residue.

[0083] It should be understood by those skilled in the art that the above embodiments are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A method for synthesizing an odorless cationic etherifying agent, characterized in that: The steps include: S1, adding hydrochloric acid into a reactor, slowly introducing trimethylamine, and reacting to obtain trimethylamine hydrochloride; S2, slowly adding epichlorohydrin into the above-mentioned reactor, and continuing the reaction under the catalytic action of the acidic catalyst; S3. After the dropwise addition of epichlorohydrin is completed, an organic amine and an alkylating agent are added in sequence to continue the reaction, and the product is post-treated to obtain the odorless cationic etherifying agent.

2. The method according to claim 1, characterized in that The molar ratio of trimethylamine, hydrochloric acid and epichlorohydrin is 1:(1-1.1):(1.05-1.3).

3. The method according to claim 1, characterized in that The acid catalyst is selected from at least one of dilute hydrochloric acid, dilute sulfuric acid and dilute nitric acid; the amount of the acid catalyst added is 0.9-1.3% of the total mass of trimethylamine, hydrochloric acid and epichlorohydrin.

4. The method according to claim 1, characterized in that In step S1, the trimethylamine should be completely introduced within 2-4 hours, and the reaction temperature is 20-50° C. After all the trimethylamine is added to the reactor, the reaction is continued for 0.5-1.5 hours.

5. The method according to claim 1, characterized in that In step S2, the temperature of the reactor is maintained at 5-15° C. during the addition of epichlorohydrin, and the addition time is 4-8 hours.

6. The method according to claim 1, characterized in that In step S2, the acidic catalyst is added after 20-40% of epichlorohydrin is added.

7. The method according to claim 1, characterized in that The organic amine is at least one of dimethylamine and diethylamine, and the added amount thereof is 1-30% of the molar amount of trimethylamine.

8. The method according to claim 1, characterized in that The alkylating agent is at least one of dimethyl carbonate and dimethyl sulfate, and the amount of the alkylating agent is 1.05-1.20 times the molar amount of the organic amine.

9. The method according to claim 1, characterized in that In step S3, after the organic amine is added into the reaction kettle, the temperature is raised to 35-45° C., the alkylating agent is added, and the temperature is maintained to continue the reaction for 3-5 hours.

10. The odorless cationic etherifying agent prepared by the method according to any one of claims 1 to 9, characterized in that: Effective content ≥69%, epichlorohydrin residue ≤5ppm, 1,3-dichloropropanol content ≤10ppm.

Images