Synthesis method of aroma-enhanced aldehyde-removing amino resin

Abstract

According to the synthetic method, the formaldehyde content of the resin is remarkably reduced by optimizing the steps of hydroxymethylation, etherification and neutralization, sedimentation and filtration, dealcoholization and dehydration and the like in combination with a Well-CD formaldehyde-removing odor-masking agent with a specific ratio, and meanwhile, the resin is endowed with excellent aroma enhancement and adsorption properties. According to the method, a functional group with an aroma enhancement function is introduced into an amino resin molecular structure, the odor problem of traditional resin is solved, and the environment-friendly target of reducing volatile odor from the source is achieved. Experimental results show that compared with a traditional method, the prepared amino resin has the advantages that the formaldehyde emission is reduced by 50% or above, the fragrance durability is improved by 30%, and the amino resin has better environmental friendliness and use experience and is suitable for the fields of coatings, adhesives, textiles and the like.

Description

Technical Field

[0001] The invention relates to a method for synthesizing an amino resin, in particular to a method for synthesizing a flavor-enhancing formaldehyde-removing amino resin. Background Art

[0002] Traditional amino resins often have some problems in application, such as strong volatile odor and high formaldehyde content. These problems not only affect the product experience, but also cause potential harm to the environment and human health. Amino resins are widely used in coatings, adhesives and textiles, and their modification and performance improvement have always been one of the research hotspots. In recent years, with the increase of environmental awareness, the market demand for low formaldehyde emission and odor-free amino resins has been increasing.

[0003] At present, common methods for reducing formaldehyde release include using formaldehyde scavengers, reducing the formaldehyde content in resins through chemical modification, etc. However, these methods often have certain limitations in practical applications, such as the unstable capture effect of formaldehyde scavengers, and the complex and costly chemical modification process.

[0004] In view of these problems, the present invention provides a new amino resin synthesis method, which significantly reduces the formaldehyde content of the product by introducing fragrance enhancement and formaldehyde removal functions during the synthesis process, while improving the odor of the product, thereby enhancing its environmental friendliness and user experience. Summary of the invention

[0005] The purpose of the present invention is to provide a method for synthesizing a fragrance-enhancing formaldehyde-removing amino resin, which significantly reduces the formaldehyde content of the product and improves its aroma retention capacity and adsorption performance through specific process steps.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A method for synthesizing a fragrance-enhancing formaldehyde-removing amino resin comprises the following steps:

[0008] Step 1) Hydroxymethylation

[0009] Add melamine and formaldehyde into the reactor through the feeding bin, stir and mix thoroughly, then add 30% liquid alkali to adjust the pH of the system to 7.0-8.0; gradually adjust the temperature in the reactor to 50-72°C until the system becomes milky white and viscous;

[0010]

[0011] Step 2) Etherification and Neutralization

[0012] 98% methanol was introduced into the reactor, and when the temperature of the reactor dropped to 48°C, hydrochloric acid was added to adjust the pH of the system to 3.5, and the reaction was continued until the system became clear and transparent; after the etherification was completed, 30% liquid alkali was used for neutralization;

[0013]

[0014] Step 3) Secondary etherification and neutralization

[0015] After neutralization is completed, 98% methanol is added, and when the temperature of the reactor reaches 48°C, hydrochloric acid is added to adjust the pH of the system to 3.5; after the etherification is completely completed, 30% liquid alkali is used for neutralization;

[0016] Step 4) Sedimentation Filtration

[0017] The reaction solution was allowed to stand and then filtered to filter out the salt and catalyst;

[0018] Step 5) Dealcoholization and dehydration

[0019] Turn on the vacuum system and slowly adjust it to -0.098MPa. Open the steam valve and raise the temperature to 90℃ until all the methanol is removed.

[0020] Step 6) Remove aldehyde and mask odor

[0021] Add well-cd formaldehyde removal and odor masking agent, stir to mix thoroughly, take samples and analyze them, then fill them.

[0022] On the basis of the above technical scheme, a method for synthesizing a flavor-enhancing formaldehyde-removing amino resin is provided, wherein the well-cd formaldehyde-removing and taste-masking agent comprises the following components:

[0023] 5.0% of 1-(5,5-dimethyl-1-cyclohexenyl)-4-penten-1-one; 90.0% of phenylacetaldehyde-1,2,3-propanetriol cyclic acetal; 5.0% of formaldehyde removal catalyst.

[0024] Beneficial effects of the present invention:

[0025] The synthesis method of the invention comprises hydroxymethylation, etherification neutralization, secondary etherification neutralization, sedimentation filtration, dealcoholization and dehydration, and aldehyde removal and odor masking. Through the above process steps, an amino resin with the functions of flavor enhancement and aldehyde removal can be prepared, thereby solving the problems of high formaldehyde content and strong odor of traditional amino resins.

[0026] The present invention adds Well-CD aldehyde removal and odor masking agent in the process of synthesizing resin, so that the product will not be turbid, and will not affect the color and turbidity. The aromatic components in the components are used to introduce functional groups with aroma enhancement functions into the resin molecular structure, such as using a special synthetic route to graft amine compounds onto the main chain or side chain of the amino resin, and these functional groups are firmly combined with the resin matrix through chemical reactions, thereby significantly improving the aroma retention capacity and adsorption performance of the resin. The volatile odor of the chemical resin is decomposed from the source, the odor structure of the traditional resin is changed, the formaldehyde content is reduced while ensuring excellent performance, and it is environmentally friendly, truly realizing green environmental protection and protecting human health. DETAILED DESCRIPTION

[0027] 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 examples, and those skilled in the art may think of other obvious variations.

[0028] A method for synthesizing a fragrance-enhancing formaldehyde-removing amino resin comprises the following steps:

[0029] 1. Hydroxymethylation

[0030] Prepare 2430kg of melamine and 4580kg of 37% formaldehyde. Add melamine and formaldehyde into the reactor through the feeding hopper, start the stirring paddle, stir for 10 minutes to fully mix, then add 10kg of 30% liquid alkali, and adjust the pH of the system to 7 to 8. Raise the temperature in the reactor to 50°C and react for half an hour until the milky white mixture slowly becomes clear. After the system becomes transparent, raise the temperature in the reactor to 72°C and continue to react for two and a half hours, and the system gradually becomes milky white and viscous.

[0031] 2. Etherification and neutralization

[0032] After the hydroxymethylation is completed, 5300 kg of 98% methanol is introduced into the reactor. When the temperature of the reactor drops to 48°C, 130 kg of 36% hydrochloric acid is added to adjust the pH of the system to 3.5. The reaction is continued for one hour, during which the system will gradually become clear and transparent. After the etherification is completed, 86 kg of 30% liquid alkali is added for neutralization.

[0033] 3. Secondary etherification and neutralization

[0034] After neutralization, add 6500 kg of 98% methanol into the reactor. When the temperature of the reactor drops to 48°C, add 100 kg of 36% hydrochloric acid, adjust the pH of the system to 3.5, and react for one hour. After etherification, add 20 kg of 30% liquid alkali for neutralization.

[0035] 4. Sedimentation Filtration

[0036] After the reaction, the solution is allowed to stand for a period of time, and the excess salt and catalyst are filtered out.

[0037] 5. Dealcoholization and dehydration

[0038] After the clear liquid after pressure filtration reaches a certain liquid level, it is sent to the dealcoholization kettle. Turn on the vacuum system and slowly adjust it to -0.098MPa, then open the steam valve and raise the temperature to 90°C until the methanol is completely removed. The dealcoholization gas is pumped to the methanol recovery condenser by a vacuum pump, and the condensate enters the methanol recovery tank A and tank B. The liquid in tanks A and B is sent to the dilute methanol temporary storage tank; the gas is absorbed by the spray tower and then pumped to the incineration device by the tail gas fan for incineration; after the absorption liquid reaches a certain concentration, it is pumped to the dilute methanol temporary storage tank and enters the distillation tower for distillation, and the dilute formaldehyde water is used in the formaldehyde production device.

[0039] 6. Remove formaldehyde and mask odor

[0040] After the amino resin has been stripped of methanol, it is sent to the preparation kettle. Open the circulating water valve to reduce the temperature in the preparation kettle to 80°C, open the outlet valve at the connection between the masking agent tank and the preparation kettle, and directly add 7.5kg Well-CD aldehyde-removing odor-masking agent [5.0% 1-(5,5-dimethyl-1-cyclohexenyl)-4-pentene-1-one (CAS No. 56973-85-4), 90.0% phenylacetaldehyde-1,2,3-propanetriol cyclic acetal (CAS No. 29895-73-6) and 5.0% aldehyde-removing catalyst] below 80°C, stir for 15 minutes to mix thoroughly. Fill after sampling and analysis.

[0041] 7. Comparison of technical effects

[0042] The formaldehyde removal rate and odor improvement effect of the aroma-enhancing formaldehyde-removing amino resin in this embodiment were verified, as well as the performance difference with common amino resin products on the market.

[0043] 1) Experimental methods

[0044] Test indicators include:

[0045] Formaldehyde removal effect: The changes in formaldehyde content were measured by gas chromatography-MS (GC-MS).

[0046] Volatile organic compound (VOC) odor intensity: measured using an electronic nose tester and subjective olfactory rating method.

[0047] Aroma persistence: Aroma residues were monitored by dynamic headspace analysis (DHS) combined with mass spectrometry detection (GC-MS).

[0048] 2) Experimental steps

[0049] Prepare 100 mL samples and place them in sealed containers to simulate high temperature (60°C) and high humidity (RH 85%) for 30 days. Take samples every 7 days to measure the formaldehyde residue, odor intensity and aroma persistence.

[0050] 3) Experimental results

[0051] index Samples of this example Control group (common amino resin products on the market) Initial formaldehyde content (mg / L) 1.2 4.8 Formaldehyde residue after 30 days (mg / L) 0.1 (91.7% decrease) 2.7 (down 43.8%) VOC odor intensity (Odor Unit) 150 (lower) 250 Aroma retention rate (%) 87 52 Humidity environment stability excellent middle

[0052] 4) Comprehensive analysis

[0053] Significant formaldehyde removal effect: The formaldehyde removal efficiency of the present invention is as high as 91.7%, which is significantly better than the control group (the maximum reduction is 43.8%), proving the synergistic effect of Well-CD formaldehyde removal and odor masking agent in chemical adsorption and formaldehyde decomposition.

[0054] Advantages of odor optimization: The VOC odor intensity of the sample of the present invention is significantly reduced, the odor is fresher, and the user experience is improved; at the same time, the subjective olfactory score shows that the aroma has a high acceptance.

[0055] The aroma persistence is significantly improved: Through a special process, the aroma-enhancing ingredients are stably introduced into the resin molecules, and the aroma retention rate reaches 87%, which is much higher than the control group (all below 55%), and has higher market competitiveness.

[0056] Outstanding environmental stability: Under high temperature and high humidity conditions, the samples of the present invention did not show any deterioration in appearance and performance, demonstrating its superior resistance to environmental influences and adaptability to a variety of application scenarios.

Claims

1. A method for synthesizing a flavoring-type formaldehyde-removing amino resin, characterized in that: The steps include: Step 1) Hydroxymethylation Add melamine and formaldehyde into the reactor through the feeding bin, stir and mix thoroughly, then add 30% liquid alkali to adjust the pH of the system to 7.0-8.0; gradually adjust the temperature in the reactor to 50-72°C until the system becomes milky white and viscous; Step 2) Etherification and Neutralization 98% methanol was introduced into the reactor, and when the temperature of the reactor dropped to 48°C, hydrochloric acid was added to adjust the pH of the system to 3.5, and the reaction was continued until the system became clear and transparent; after the etherification was completed, 30% liquid alkali was used for neutralization; Step 3) Secondary etherification and neutralization After neutralization is completed, 98% methanol is added, and when the temperature of the reactor reaches 48°C, hydrochloric acid is added to adjust the pH of the system to 3.5; after the etherification is completely completed, 30% liquid alkali is used for neutralization; Step 4) Sedimentation Filtration The reaction solution was allowed to stand and then filtered to filter out the salt and catalyst; Step 5) Dealcoholization and dehydration Turn on the vacuum system and slowly adjust it to -0.098MPa. Open the steam valve and raise the temperature to 90℃ until all the methanol is removed. Step 6) Remove aldehyde and mask odor Add well-cd formaldehyde removal and odor masking agent, stir to mix thoroughly, take samples and analyze them, then fill them.

2. A method for synthesizing a flavoring-type formaldehyde-removing amino resin, characterized in that: The well-cd aldehyde-removing and taste-masking agent comprises the following components: 5.0% 1-(5,5-dimethyl-1-cyclohexenyl)-4-penten-1-one; 90.0% of phenylacetaldehyde-1,2,3-propanetriol cyclic acetal; 5.0% formaldehyde removal catalyst.

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