Preparation method of anti-yellowing agent HN-130
Through a new preparation method, the problems of high requirements for raw material purity and complex solvent purification in the existing process are solved, and the efficient and low-cost preparation of anti-yellow agent HN-130 is achieved, which improves the purity and yield of the product.
Patent Information
- Application Number
- CN202411629525.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-02-28
AI Technical Summary
The existing process for preparing the anti-yellow agent HN-130 has high requirements for raw material purity, high production cost, and difficult to recycle solvents. The solvent purification process is complex, which affects product purity and yield.
Using a preparation method, the anti-yellowicant HN-130 is prepared by dissolving hexamethylenediisocyanate and metadimethylhydrazine in a solvent, respectively, and then adding dropwise at a set temperature and reacting thoroughly, followed by solid-liquid separation and vacuum drying to obtain the anti-yellow agent HN-130.
The requirements for raw material purity are reduced, the simplicity and operability of the process are improved, the recycling application and purification process of solvents are achieved, and the purity and yield of the product are improved.
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Figure CN119528770A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of chemical materials, and in particular to a preparation method of an anti-yellowing agent HN-130. Background Art
[0002] As one of the necessary additives in the spandex production process, HN-130 can be used to prevent polyurethane from yellowing and is widely used in the polyurethane industry.
[0003] The main disadvantages of the existing preparation process are: high purity requirements for raw materials, especially UDMH, resulting in high production costs; at the same time, high requirements for the synthesis process, difficulty in solvent recycling, and complex solvent purification process; in addition, the solubility of raw materials in existing solvents is poor, resulting in incomplete reaction and affecting the yield, and easy to produce impurities, thereby limiting product purity. Summary of the invention
[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for preparing an anti-yellowing agent HN-130.
[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing an anti-yellowing agent HN-130 comprises the following steps: Step 1: dissolving hexamethylene diisocyanate and unsymmetrical dimethylhydrazine in solvents respectively to prepare a hexamethylene diisocyanate-solvent mixed solution and an unsymmetrical dimethylhydrazine-solvent mixed solution; Step 2: adding the hexamethylene diisocyanate-solvent mixed solution dropwise to the unsymmetrical dimethylhydrazine-solvent mixed solution at a set temperature, while maintaining a constant temperature and continuously stirring until the two are fully reacted; Step 3: After the reaction is completed, solid-liquid separation is performed to collect the solid generated by the reaction; Step 4: vacuum drying the solid separated in step 3 to obtain the anti-yellowing agent HN-130.
[0006] Preferably, the solvent includes one or two of C2~C4 alcohols, C2~C4 polyhalogenated alkanes or olefins, C2~C4 cyclic ethers, and C2~C4 alkyl mononitriles.
[0007] Preferably, the solute content in the solvent is ≥95%, the water content in the solvent is ≤0.5%, the partial hydrazone content in the solvent is ≤0.5%, and the unsymmetrical dimethylhydrazine content in the solvent is ≤0.4%.
[0008] Preferably, in step 1, the concentration of hexamethylene diisocyanate in the hexamethylene diisocyanate-solvent mixed solution is 2.0~3.5 mol / L, and the concentration of unilateral dimethylhydrazine in the unilateral dimethylhydrazine-solvent mixed solution is 2.5~5.0 mol / L; in step 2, the volume ratio of the hexamethylene diisocyanate-solvent mixed solution to the unilateral dimethylhydrazine-solvent mixed solution is 1:(1.4~1.6).
[0009] Preferably, in step 2, when the hexamethylene diisocyanate-solvent mixed solution is added dropwise, the temperature is set to -10~20°C.
[0010] Preferably, in step 2, when the hexamethylene diisocyanate-solvent mixed solution is added dropwise, the temperature is set to 0-10°C.
[0011] Preferably, the method for purifying the solvent before use is specifically: adding the treating agent into the solvent purification device, and then adding the solvent into the purification device in batches, heating and distilling, obtaining the purified solvent that meets the technical requirements and then recycling it.
[0012] Preferably, the solvent is a new solvent, a recycled solvent or a purified solvent.
[0013] Preferably, the solvent is applied 2 to 4 times.
[0014] Preferably, the solvent is applied three times.
[0015] Preferably, the treatment agent is one of an alkali metal salt, an alkaline earth metal salt, and an acidic treatment agent.
[0016] Preferably, the alkali metal salt and alkaline earth metal salt include sulfate and carbonate; and the acidic treatment agent includes concentrated sulfuric acid and phosphorus pentoxide.
[0017] Preferably, the sulfate and carbonate include magnesium sulfate, sodium carbonate and the like.
[0018] Preferably, the water content in the solvent is ≤30%, and the partial hydrazone content in the solvent is ≤1.2%.
[0019] The beneficial effects of the present invention are: The method provided by the invention has low requirements on the purity of raw materials, wherein the purity of unsymmetrical dimethylhydrazine is ≥90%; the method provided by the invention has simple process and strong operability; the solvent can be recycled, and the solvent purification process is simple and has a wide application range (water content ≤30%; unsymmetrical hydrazone content ≤1.2%); compared with the existing synthesis process, the method provided by the invention has high yield (≥95%) for preparing the anti-yellowing agent HN-130, high product purity (≥99%), and low chroma (≤20 black cents). BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is the HPLC chromatogram of HN-130 prepared in Example 1 of the present invention; Figure 2 This is the high performance liquid chromatogram of HN-130 prepared in Example 2 of the present invention. DETAILED DESCRIPTION
[0021] The technical solutions of the present invention will be described clearly and completely below in conjunction with embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Example 1
[0022] Solvent purification: first add a certain amount of solvent into the purification device, then add concentrated sulfuric acid, and finally add C2~C4 alcohol solvents into the purification device in batches, heat up and distill, and obtain the purified C2~C4 alcohol solvents for recycling; Preparation of anti-yellowing agent HN-130: Dissolve hexamethylene diisocyanate and unsymmetrical dimethyl hydrazine in C2~C4 alcohol solvents respectively to prepare hexamethylene diisocyanate-C2~C4 alcohol solvent mixed solution and unsymmetrical dimethyl hydrazine-C2~C4 alcohol solvent mixed solution; at a temperature of -10~20°C, add the hexamethylene diisocyanate-C2~C4 alcohol solvent mixed solution dropwise to the unsymmetrical dimethyl hydrazine-C2~C4 alcohol solvent mixed solution, while maintaining a constant temperature and continuously stirring until the two are fully reacted; after the reaction is completed, perform solid-liquid separation, and collect the solid generated by the reaction; vacuum dry the separated solid to obtain the anti-yellowing agent HN-130. Example 2
[0023] Solvent purification: adding alkali metal carbonate to the solvent purification device, and then adding C2~C4 alkyl mononitrile solvent to the purification device in batches, heating and distilling to obtain the purified C2~C4 alkyl mononitrile solvent for recycling; Preparation of anti-yellowing agent HN-130: Dissolve hexamethylene diisocyanate and unsymmetrical dimethyl hydrazine in C2~C4 alkyl mononitrile solvents respectively to prepare a hexamethylene diisocyanate-C2~C4 alkyl mononitrile solvent mixed solution and an unsymmetrical dimethyl hydrazine-C2~C4 alkyl mononitrile alcohol solvent mixed solution; at a temperature of 0~10°C, dropwise add the hexamethylene diisocyanate-C2~C4 alkyl mononitrile solvent mixed solution into the unsymmetrical dimethyl hydrazine-C2~C4 alkyl mononitrile solvent mixed solution, while maintaining a constant temperature and continuously stirring until the two are fully reacted; after the reaction is completed, perform solid-liquid separation, and collect the solid generated by the reaction; vacuum dry the separated solid to obtain the anti-yellowing agent HN-130.
[0024] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A method for preparing an anti-yellowing agent HN-130, characterized in that: The following steps are involved: Step 1: dissolving hexamethylene diisocyanate and unsymmetrical dimethylhydrazine in solvents respectively to prepare a hexamethylene diisocyanate-solvent mixed solution and an unsymmetrical dimethylhydrazine-solvent mixed solution; Step 2: adding the hexamethylene diisocyanate-solvent mixed solution dropwise to the unsymmetrical dimethylhydrazine-solvent mixed solution at a set temperature, while maintaining a constant temperature and continuously stirring until the two are fully reacted; Step 3: After the reaction is completed, solid-liquid separation is performed to collect the solid generated by the reaction; Step 4: vacuum drying the solid separated in step 3 to obtain the anti-yellowing agent HN-130.
2. The method for preparing the anti-yellowing agent HN-130 according to claim 1, characterized in that: The solvent includes one or two of C2-C4 alcohols, C2-C4 polyhalogenated alkanes or olefins, C2-C4 cyclic ethers, and C2-C4 alkyl mononitriles.
3. The method for preparing the anti-yellowing agent HN-130 according to claim 1, characterized in that: The solute content in the solvent is ≥95%, the water content in the solvent is ≤0.5%, the partial hydrazone content in the solvent is ≤0.5%, and the unsymmetrical dimethylhydrazine content in the solvent is ≤0.4%.
4. The method for preparing the anti-yellowing agent HN-130 according to claim 1, characterized in that: In step 1, in the hexamethylene diisocyanate-solvent mixed solution, the concentration of hexamethylene diisocyanate is 2.0-3.5 mol / L, and in the unsymmetrical dimethylhydrazine-solvent mixed solution, the concentration of unsymmetrical dimethylhydrazine is 2.5-5.0 mol / L; In step 2, the volume ratio of the hexamethylene diisocyanate-solvent mixed solution to the unsymmetrical dimethylhydrazine-solvent mixed solution is 1:(1.4-1.6).
5. The method for preparing the anti-yellowing agent HN-130 according to claim 1, characterized in that: In step 2, when the hexamethylene diisocyanate-solvent mixed solution is added dropwise, the temperature is set to -10~20°C.
6. The method for preparing the anti-yellowing agent HN-130 according to claim 1, characterized in that: The method for purifying the solvent before use is specifically: adding the treating agent into the solvent purification device, then adding the solvent into the purification device in batches, heating and distilling, obtaining the purified solvent and then recycling it.
7. The method for preparing the anti-yellowing agent HN-130 according to claim 6, characterized in that: The treatment agent is one of an alkali metal salt, an alkaline earth metal salt and an acidic treatment agent.
8. The method for preparing the anti-yellowing agent HN-130 according to claim 7, characterized in that: The alkali metal salt and alkaline earth metal salt include sulfate and carbonate; the acidic treatment agent includes concentrated sulfuric acid and phosphorus pentoxide.
9. The method for preparing the anti-yellowing agent HN-130 according to claim 8, characterized in that: The sulfates and carbonates include magnesium sulfate, sodium carbonate and the like.
10. The method for preparing the anti-yellowing agent HN-130 according to claim 6, characterized in that: The water content in the solvent is ≤30%, and the partial hydrazone content in the solvent is ≤1.2%.