An antibacterial, formaldehyde-removing and odor-removing material, its preparation method and application

Abstract

The present invention discloses a synthesis method and application of an additive with antibacterial, formaldehyde-removing and odor-removing effects, comprising the following steps: taking an appropriate amount of 2-methylimidazole, wetting the powder with water of the same mass; slowly dropping hydrochloric acid, stirring and acidifying for a certain time, then carrying out solid-liquid separation of the solution at low temperature, drying the obtained solid to obtain 2-methylimidazole hydrochloride powder; dissolving the above powder in a lower alcohol, gradually heating up in a reactor equipped with a stirring device, a titration device and a reflux condenser, taking an appropriate amount of dicyandiamide powder and dissolving it in a lower alcohol, slowly dropping it into the 2-methylimidazole hydrochloride solution, mixing evenly and then gradually raising the temperature for reaction; after the above reaction is completed, recovering the lower alcohol by vacuum distillation and drying to obtain a white powdery solid product. This production method has a simple process, does not use precious metals, and can endow the coating with antibacterial, formaldehyde-removing and odor-removing effects with a relatively small amount.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and specifically relates to an antibacterial, formaldehyde-removing and odor-removing material, a preparation method thereof and an application thereof. Background Art

[0002] As the second largest paint producer and consumer in the world, paints are closely related to people's lives. With the economic development and the change of consumption concepts caused by people's needs under the epidemic, the concerns about pollutants such as bacteria, formaldehyde and TVOC have made interior wall paints with antibacterial, formaldehyde-removing and odor-removing functions increasingly favored by consumers.

[0003] Among the existing paint additives with antibacterial, formaldehyde-removing and odor-removing functions, inorganic materials mainly select photocatalytic materials, which utilize their antibacterial properties and catalytic degradation of pollutants such as formaldehyde under visible light or ultraviolet light excitation. However, this technology is also limited by light. In the case of relying solely on photocatalytic materials and lacking an excitation light source, both antibacterial and formaldehyde-removing performances are lacking. For example, CN 202110047075.5 can only have a certain antibacterial rate under ultraviolet light conditions; CN202111311886.8 introduces an antibacterial and formaldehyde-removing agent based on photocatalytic materials, compounded with silver, rare earth and plant extracts. However, the use of precious metals and rare earth elements results in a high cost of this additive, and at the same time, the additive production process is complex and difficult to be actually applied. For organic materials, such as CN 202010461881.2, which introduces an additive prepared from chitosan derivatives, the formaldehyde-removing effect is still unsatisfactory even when the addition amount reaches 15%. The above methods all have deficiencies. Therefore, it is urgent to develop an antibacterial, formaldehyde-removing and odor-removing material with low cost and excellent effects. Summary of the Invention

[0004] One of the purposes of the present invention is to solve the shortcomings and deficiencies of the existing paint additive technology, and provide a functional material with antibacterial, formaldehyde-removing and odor-removing functions and a preparation method thereof.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An antibacterial, formaldehyde-removing and odor-removing material, whose chemical name is N-carbamoyl-2-methyl-1H-imidazole-1-carboximidamide hydrochloride, and its structural formula is shown in formula (Ⅰ):

[0007] 。

[0008] (Ⅰ)

[0009] The preparation method of the antibacterial, formaldehyde-removing and odor-removing material includes the following steps:

[0010] (1) Take 2-methylimidazole and moisten the powder with the same mass of water.

[0011] (2) Slowly drop hydrochloric acid into the system in step 1. After stirring and acidifying, perform solid-liquid separation on this solution at low temperature, and dry the obtained solid to obtain 2-methylimidazole hydrochloride powder;

[0012] (3) Dissolve the above-mentioned 2-methylimidazole hydrochloride powder in a lower alcohol to obtain a 2-methylimidazole hydrochloride solution, transfer it into a reactor equipped with a stirring device, a titration device and a reflux condenser, and gradually heat up to 60 °C; Take dicyandiamide powder, dissolve it in a lower alcohol to obtain a dicyandiamide solution, slowly drop the dicyandiamide solution into the 2-methylimidazole hydrochloride solution, and gradually increase the temperature for reaction after mixing evenly;

[0013] (4) After the above reaction is completed, recover the lower alcohol by vacuum distillation and dry to obtain a white powdery solid product.

[0014] Preferably, in the above preparation method, the molar concentration of the hydrochloric acid in step (2) is 0.5-3.0 mol / L, the acidification time is 0.1-1 h, and the low-temperature separation temperature is 0-5 °C.

[0015] Preferably, in the above preparation method, the lower alcohol in step (3) is one or at least two of methanol, ethanol or propanol.

[0016] Preferably, in the above preparation method, the molar ratio of dicyandiamide to the amino group in 2-methylimidazole hydrochloride in step (3) is 0.5-5:1.

[0017] Preferably, in the above preparation method, the dropping speed in step (3) is 15-20 μL / s, the temperature is gradually increased by 5 °C every 10 min, and the reaction temperature is increased to a maximum of 95 °C; the reaction time is 2-6 h.

[0018] The N-carbamoyl-2-methyl-1H-imidazole-1-carboximidamide hydrochloride of the present invention has good antibacterial, formaldehyde-removing and odor-removing properties, good compatibility and stability with coatings, and can be used to prepare coatings with antibacterial, formaldehyde-removing and odor-removing functions. The coating can be a water-based coating, a solvent-based coating or an inorganic coating.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The preparation process of the antibacterial, formaldehyde-removing and odor-removing material of the present invention is simple, the raw materials are inexpensive, and precious metals are not required.

[0021] (2) The antibacterial, formaldehyde-removing and odor-removing material of the present invention uses a low-boiling solvent, which can be recovered by vacuum concentration, and the recovered solvent can be reused, avoiding environmental pollution caused by reaction solvents.

[0022] (3) The antibacterial, formaldehyde-removing and odor-removing additive of the present invention can simultaneously achieve antibacterial, formaldehyde-removing and odor-removing effects. When the addition amount is 0.5%, the antibacterial rates against Escherichia coli and Staphylococcus aureus can reach 95%, and the formaldehyde-removing rate is about 90%, reducing the dosage of coating additives. Description of the Drawings

[0023] Figure 1 It is an infrared spectrogram obtained by FT-IR detection of the antibacterial, formaldehyde-removing and odor-removing additives prepared in each example and comparative example.

[0024] Figure 2 It is the nuclear magnetic resonance C spectrum of N-carbamoyl-2-methyl-1H-imidazole-1-carboximidamide hydrochloride obtained in Example 1. Detailed Embodiments

[0025] The technical solution of the present invention will be further described below through specific embodiments.

[0026] Unless otherwise specified, various raw materials of the present invention can be purchased commercially or prepared by conventional methods in the technical field.

[0027] Example 1

[0028] A preparation method of an antibacterial, formaldehyde-removing and odor-removing material includes the following steps: (1) Take 2 g of 2-methylimidazole and moisten the powder with the same mass of water; (2) Slowly drop 1.0 mol / L hydrochloric acid into the system in step 1, with an addition amount of 10 mL, stir and acidify for 0.5 h, perform solid-liquid separation on the solution at 4°C, and dry the obtained solid to obtain 2-methylimidazole hydrochloride powder; (3) Dissolve the above powder in a mixed solvent of 70 ml of ethanol and propanol, gradually heat up to 60°C in a reactor equipped with a stirring device, a titration device, and a reflux condenser, take 1.88 g of dicyandiamide powder, dissolve it in a mixed solvent of 30 ml of ethanol and propanol, slowly drop the dicyandiamide solution into the 2-methylimidazole hydrochloride solution, and gradually raise the temperature to 90°C after mixing evenly for reaction; (4) After the above reaction is completed, recover the lower alcohols by vacuum distillation and dry to obtain a white powdery solid product, which is N-carbamoyl-2-methyl-1H-imidazole-1-carboximidamide hydrochloride. The nuclear magnetic data of the obtained product is as Figure 2As shown in the figure, the chemical shift of 1-C in the figure is 136.7 ppm, which is the substitution position of the heterocyclic carbon; the chemical shift values of 2-C and 3-C are 124.1 ppm and 121.5 ppm respectively, which are the C=C double bonds in the heterocycle; the chemical shift of 8-C is 14.1 ppm, which is the primary carbon connected to the heterocycle; the chemical shift of 12-C is 114.7 ppm, indicating that the C≡N bond in the biguanide is opened and successfully combines with the N on 2-methylimidazole to form a C-N bond, resulting in a low-field shift of the α-position carbon atom due to electronegativity; the chemical shift of 15-C is 133.1 ppm, which is the methyleneimine bond.

[0029] Example 2

[0030] A preparation method of an antibacterial, formaldehyde-removing and odor-removing material comprises the following steps: (1) Take 4 g of 2-methylimidazole and moisten the powder with the same mass of water; (2) Slowly drop 1.0 mol / L hydrochloric acid into the system in step 1, with an addition amount of 20 mL, stir and acidify for 0.5 h, carry out solid-liquid separation on this solution at 4 °C, and dry the obtained solid to obtain 2-methylimidazole hydrochloride powder; (3) Dissolve the above powder in a mixed solvent of 70 ml of ethanol and propanol, gradually heat up to 60 °C in a reactor equipped with a stirring device, a titration device and a reflux condenser, take 3.76 g of dicyandiamide powder, dissolve it in a mixed solvent of 30 ml of ethanol and propanol, slowly drop the dicyandiamide solution into the 2-methylimidazole hydrochloride solution, and gradually raise the temperature to 90 °C for reaction after mixing evenly; (4) After the above reaction is completed, recover the lower alcohols by vacuum distillation and dry to obtain a white powdery solid product, which is N-carbamoyl-2-methyl-1H-imidazole-1-carboximidamide hydrochloride.

[0031] Example 3

[0032] A preparation method of an antibacterial, formaldehyde-removing and odor-removing material comprises the following steps: (1) Take 6 g of 2-methylimidazole and moisten the powder with the same mass of water; (2) Slowly drop 1.0 mol / L hydrochloric acid into the system in step 1, with an addition amount of 30 mL, stir and acidify for 0.5 h, carry out solid-liquid separation on this solution at 4 °C, and dry the obtained solid to obtain 2-methylimidazole hydrochloride powder; (3) Dissolve the above powder in a mixed solvent of 70 ml of ethanol and propanol, gradually heat up to 60 °C in a reactor equipped with a stirring device, a titration device and a reflux condenser, take 5.64 g of dicyandiamide powder, dissolve it in a mixed solvent of 30 ml of ethanol and propanol, slowly drop the dicyandiamide solution into the 2-methylimidazole hydrochloride solution, and gradually raise the temperature to 90 °C for reaction after mixing evenly; (4) After the above reaction is completed, recover the lower alcohols by vacuum distillation and dry to obtain a white powdery solid product, which is N-carbamoyl-2-methyl-1H-imidazole-1-carboximidamide hydrochloride.

[0033] Comparative Example 1

[0034] Compared with Example 1, Control Example 1 does not wet the powder with water of the same mass, and the other steps are the same.

[0035] Compared with Example 1, Control Example 2 is different in that the mixed solvent of ethanol and propanol in step (3) of Example 1 is replaced with water, and the other steps are the same.

[0036] Compared with Example 1, in Control Example 3, the dicyandiamide solution in step (3) was added all at once, and the dripping rate of the dicyandiamide solution was not controlled. The other steps were the same.

[0037] Compared with Example 1, in Control Example 4, the dicyandiamide solution in step (3) was added at 90° C., rather than first adding it and then heating it to 90° C., and the other steps were the same.

[0038] The antibacterial effect of the antibacterial and formaldehyde-removing odor-removing additives prepared in Examples 1 to 3 and Comparative Examples 1 to 4 in the coating is 0.5% added. The antibacterial test refers to the standard "GB 21866-2008 Determination of antibacterial properties and antibacterial effects of antibacterial coatings (paint films)", and the results are shown in Table 1.

[0039] Table 1. Test results of coating antibacterial and antiviral

[0040]

[0041] The antibacterial and formaldehyde-removing and odor-removing effects of the antibacterial and formaldehyde-removing and odor-removing additives prepared in Examples 1 to 3 and Comparative Examples 1 to 4 in the coating are shown in Table 2, with an addition amount of 0.5%. The antibacterial test refers to the standard "JC / T 1074-2021 Purification Performance of Indoor Air Purification Functional Coating Materials".

[0042] Table 2. Test results of paint formaldehyde removal and odor removal

[0043]

[0044] The antibacterial and formaldehyde-removing odor-removing additives prepared in some embodiments and comparative examples were subjected to FT-IR detection, and the infrared spectra obtained were shown in FIG. Figure 1 .

[0045] In Example 1, 1693 cm -1 [-HN(C=NH)NH 2 ] is the absorption peak of C=N stretching vibration, 1508cm -1 NH 3 + The bending vibration absorption peak at 1425 cm -1The vibration peak appearing at [specific location] is the stretching vibration peak of C-N-C. At the same time, in addition to the characteristic peaks of the guanidine compound, the antibacterial, formaldehyde-removing and odor-removing additive also has partial characteristic absorption peaks of 2-methylimidazole and dicyandiamide. The compound was also successfully synthesized in Comparative Example 1. However, due to the hygroscopicity of 2-methylimidazole, direct acidification of 2-methylimidazole during the synthesis process led to agglomeration and uneven acidification of the powder, resulting in weak peaks and unclear peak shapes in the finally obtained product; in the synthesis process of Comparative Example 3, all the dicyandiamide solution was added at once, resulting in incomplete reaction between dicyandiamide and 2-methylimidazole, and the peak shape of dicyandiamide was more prominent in the infrared spectrum; in Comparative Example 4, the dicyandiamide solution was unstable under high heat conditions, so adding the dicyandiamide solution at 90 °C also caused the synthesis reaction to not proceed completely.

Claims

1. An antibacterial, formaldehyde-removing and odor-removing material, characterized in that its chemical name is 2-methylimidazole biguanide hydrochloride, and its structural formula is shown in Formula (Ⅰ): （Ⅰ）。 2. A preparation method of the antibacterial, formaldehyde-removing and odor-removing material according to Claim 1, characterized in that it comprises the following steps: (1) Take 2-methylimidazole and moisten the powder with water of the same mass; (2) Slowly drop hydrochloric acid into the system in step (1), stir and acidify, then carry out solid-liquid separation on this solution at low temperature, and dry the obtained solid to obtain 2-methylimidazole hydrochloride powder; (3) Dissolve the above-mentioned 2-methylimidazole hydrochloride powder in a lower alcohol to obtain a 2-methylimidazole hydrochloride solution, transfer it to a reactor equipped with a stirring device, a titration device and a reflux condenser, and gradually heat up to 60 °C; Take dicyandiamide powder, dissolve it in a lower alcohol to obtain a dicyandiamide solution, slowly drop the dicyandiamide solution into the 2-methylimidazole hydrochloride solution, mix evenly and then gradually raise the temperature for reaction; (4) After the above reaction is completed, recover the lower alcohol by vacuum distillation and dry to obtain a white powdery solid product.

3. The preparation method according to Claim 2, characterized in that, in step (2), the molar concentration of the hydrochloric acid is 0.5 - 3.0 mol / L, the acidification time is 0.1 - 1 h, and the low-temperature separation temperature is 0 - 5 °C.

4. The preparation method according to Claim 2, characterized in that, the lower alcohol in step (3) is one or at least two of methanol, ethanol or propanol.

5. The preparation method according to Claim 2, characterized in that, in step (3), the molar ratio of dicyandiamide to the amino group in 2-methylimidazole hydrochloride is 0.5 - 5:

1.

6. The preparation method according to Claim 2, characterized in that, in step (3), the dropping speed is 15 - 20 μL / s, the temperature is gradually raised by 5 °C every 10 min, and the reaction temperature is raised to a maximum of 95 °C; the reaction time is 2 - 6 h.

7. Application of the 2-methylimidazole biguanide hydrochloride according to Claim 1 as an additive for antibacterial, formaldehyde-removing and odor-removing functional coatings.

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