Antibacterial formaldehyde-free impregnating adhesive and preparation process thereof

Abstract

The invention discloses an antibacterial formaldehyde-free impregnating adhesive and a preparation process thereof, and belongs to the technical field of impregnating adhesives. The antibacterial formaldehyde-free impregnating adhesive comprises the following raw materials in parts by weight: 45-70 parts of a waterborne polyurethane dispersion, 0.5-1 part of a defoaming agent, 2-3 parts of a wetting agent, 1-1.5 parts of a thickening agent, 2-5 parts of an antibacterial agent, 5-8 parts of a flame retardant and 30-50 parts of deionized water. The antibacterial agent is prepared by the following steps: reacting diethanol amine with 1-chlorotridecane to generate a tertiary amine compound, reacting with 1, 2-bis (2-chloroethoxy) ethane to generate a quaternary ammonium salt compound, reacting with 5-chloro-1-pentyne to generate an alkynyl compound, and finally reacting with azidonicotinic acid formyl. The antibacterial formaldehyde-free impregnating adhesive prepared by the invention has excellent antibacterial property and flame retardant property, does not release formaldehyde, and meets the requirements of environmental protection, safety and high performance.

Description

Technical Field

[0001] The present invention relates to the technical field of impregnating adhesives, and in particular to an antibacterial and formaldehyde-free impregnating adhesive and its preparation process. Background Art

[0002] With the improvement of people's living standards, the awareness of health and environmental protection has been continuously strengthened, and the requirements for environmental protection-related standards at home and abroad have also been continuously improved. During the use of impregnating adhesives, free formaldehyde will be slowly released, causing indoor air pollution and affecting people's physical health. In addition, the problems of easy mildew and corrosion of wood not only affect its mechanical properties but also limit its use in many fields. Moreover, the disadvantage of flammability of wood also poses a potential threat to people's safety. In recent years, antibacterial impregnating adhesives have gradually attracted attention, but most of the existing antibacterial impregnating adhesives still contain formaldehyde release, and there are problems of poor antibacterial persistence and poor flame retardant effect.

[0003] The Chinese patent application with the publication number CN108276942A discloses an impregnating adhesive for ultra-low formaldehyde impregnated paper and its preparation method. The impregnating adhesive disclosed in this patent application is composed of the following components: melamine-modified ultra-low formaldehyde grade urea-formaldehyde resin, modifier (1), modifier (2), and penetrant; this ultra-low formaldehyde impregnating adhesive for paper has a low formaldehyde release, and when the impregnated paper manufactured with this invention's impregnating adhesive is used in the production of formaldehyde-free artificial boards with impregnated paper facings, it exhibits high water resistance and high surface performance, but it does not add antibacterial components, resulting in poor antibacterial properties. Therefore, developing an antibacterial and formaldehyde-free impregnating adhesive with no formaldehyde release, high efficiency in antibacterial, and excellent flame retardant performance is of great significance for meeting the requirements of environmental protection, safety, and high performance. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an antibacterial and formaldehyde-free impregnating adhesive and its preparation process.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions: An antibacterial and formaldehyde-free impregnating adhesive, comprising the following raw materials in parts by weight: 45 - 70 parts of aqueous polyurethane dispersion, 0.5 - 1 part of defoamer, 2 - 3 parts of wetting agent, 1 - 1.5 parts of thickener, 2 - 5 parts of antibacterial agent, 5 - 8 parts of flame retardant, 30 - 50 parts of deionized water; The antibacterial agent is prepared by reacting diethanolamine with 1-chlorotridecane to form a tertiary amine compound, then reacting with 1,2-bis(2-chloroethoxy)ethane to form a quaternary ammonium salt compound, then reacting with 5-chloro-1-pentyne to form an alkynyl compound, and finally reacting with nicotinic acid azide formyl.

[0006] The antibacterial agent is prepared by the following method: S1: Diethanolamine reacts with 1-chlorotridecane under the action of potassium carbonate to form a tertiary amine compound. The reaction equation is shown as follows:

[0007] S2: The tertiary amine compound reacts with 1,2-bis(2-chloroethoxy)ethane to form a quaternary ammonium salt compound. The reaction equation is shown as follows:

[0008] S3: The quaternary ammonium salt compound reacts with 5-chloro-1-pentyne under the action of sodium hydroxide to form an alkynyl compound. The reaction equation is shown as follows:

[0009] S4: The alkynyl compound reacts with nicotinic acid azide formyl in the presence of a catalyst copper sulfate and a reducing agent sodium ascorbate to obtain an antibacterial agent. The reaction equation is shown as follows:

[0010] In the step S1, the molar ratio of diethanolamine to 1-chlorotridecane in the feed is 1:(0.8 - 1.1).

[0011] In the step S2, the molar ratio of the tertiary amine compound to 1,2-bis(2-chloroethoxy)ethane in the feed is 2:(0.9 - 1.1).

[0012] In the step S3, the molar ratio of the quaternary ammonium salt compound to 5-chloro-1-pentyne in the feed is 1:(4 - 4.5).

[0013] In the step S4, the molar ratio of the alkynyl compound to nicotinic acid azide formyl in the feed is 1:(4.2 - 4.8).

[0014] The flame retardant is prepared by the following method: N1: 3-Aminopropylmethyldimethoxysilane reacts with [4-(vinyloxy)phenyl]methanol to form a hydroxyl compound. The reaction equation is shown as follows:

[0015] N2: The hydroxyl compound reacts with phenylphosphonic dichloride to form a flame retardant. The reaction equation is shown as follows:

[0016] In the step N1, the molar ratio of 3-aminopropylmethyldimethoxysilane to [4-(vinyloxy)phenyl]methanol in the feed is 1:2; in the step N2, the molar ratio of the hydroxyl compound to phenylphosphonic dichloride in the feed is 1:0.8.

[0017] The defoamer is an organosilicon defoamer; the wetting agent is one of sodium dodecyl sulfonate and fatty acid polyoxyethylene ether; the thickener is sodium carboxymethyl cellulose.

[0018] A preparation process of an antibacterial formaldehyde-free impregnating adhesive includes the following steps: (1) Weigh by parts by weight: 45-70 parts of aqueous polyurethane dispersion, 0.5-1 part of defoamer, 2-3 parts of wetting agent, 1-1.5 parts of thickener, 2-5 parts of antibacterial agent, 5-8 parts of flame retardant, and 30-50 parts of deionized water; (2) Stir the aqueous polyurethane dispersion, deionized water, defoamer, and wetting agent evenly, add the antibacterial agent and flame retardant and stir evenly, and then add the thickener and stir evenly to obtain the formaldehyde-free impregnating adhesive.

[0019] Due to the above technical solutions, the beneficial effects of the present invention include: (1) The antibacterial agent prepared by the present invention has multiple antibacterial mechanisms such as destroying the integrity of cell membranes and inhibiting the growth and reproduction of bacteria, making the impregnating adhesive have excellent antibacterial properties; (2) The flame retardant prepared by the present invention achieves efficient flame retardancy through multi-path synergy. Specific embodiments

[0020] The following is further described in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0021] Example 1 Preparation of antibacterial agent: S1: Add 1000 ml of absolute ethanol and 1 mol of diethanolamine into a reaction kettle, stir and mix evenly, heat up to 75 °C, dropwise add 0.8 mol of 1-chlorotridecane, finish dropping in 30 min, reflux and react for 40 h, add 1.2 mol of potassium carbonate and continue to react for 4 h, cool to room temperature, carry out reduced pressure distillation at 50 °C for 2 h, add 1200 ml of ether to dissolve, wash with deionized water (500 ml × 3 times), dry the organic phase with 100 g of anhydrous magnesium sulfate, filter, carry out reduced pressure distillation at 30 °C for 2 h to obtain a tertiary amine compound; the nuclear magnetic resonance hydrogen spectrum data thereof is as follows: 1 HNMR (300 MHz, DMSO-d6) δ 4.92 – 4.82 (m, 2H), 3.57 (dt, J = 6.4, 5.7 Hz, 4H),2.71 (t, J = 5.6 Hz, 4H), 2.61 (t, J = 6.1 Hz, 2H), 1.47 (ttd, J = 6.9, 6.0,1.0 Hz, 2H), 1.40 – 1.21 (m, 20H), 0.96 – 0.82 (m, 3H).

[0022] S2: Under nitrogen protection, add 500 ml of absolute ethanol and 0.2 mol of tertiary amine compound into the reaction kettle, stir and mix evenly, heat up to 70 °C, dropwise add 0.09 mol of 1,2-bis(2-chloroethoxy)ethane, finish dropping in 30 min, reflux and react for 45 h, cool to room temperature, carry out vacuum distillation at 40 °C for 2 h, add 500 ml of a mixed solution of ethyl acetate and absolute ethanol (volume ratio of ethyl acetate to absolute ethanol is 8:2) for recrystallization, stand still for 10 h under ice bath, filter, and dry in vacuum at 45 °C for 10 h to obtain the quaternary ammonium salt compound; the 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ 5.42 (t, J = 7.2 Hz, 4H), 3.90 – 3.79 (m,12H), 3.77 – 3.70 (m, 12H), 3.66 (s, 4H), 3.58 (d, J = 8.7 Hz, 4H), 1.70 (tt,J = 8.7, 6.2 Hz, 4H), 1.46 – 1.19 (m, 40H), 0.96 – 0.82 (m, 6H).

[0023] S3: Add 600 ml of absolute DMF, 0.1 mol of quaternary ammonium salt compound and 0.5 mol of sodium hydroxide into the reaction kettle, stir for 30 min, add 0.4 mol of 5-chloro-1-pentyne, heat up to 70 °C, react for 10 h, cool to room temperature, filter, carry out vacuum distillation at 60 °C for 1 h, add 400 ml of methanol to precipitate solids, filter, wash with 400 ml of 80 wt% methanol aqueous solution, and dry in vacuum at 50 °C for 20 h to obtain the alkynyl compound; the 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ 3.81 (dtd, J =5.3, 2.7, 0.8 Hz, 12H), 3.73 (dtd, J = 6.2, 4.1, 0.7 Hz, 12H), 3.66 (s, 4H),3.56 (d, J = 12.4 Hz, 8H), 3.46 (t, J = 8.7 Hz, 4H), 2.59 – 2.48 (m, 8H),2.06 (t, J = 2.5 Hz, 4H), 1.81 – 1.62 (m, 12H), 1.46 – 1.20 (m, 40H), 0.96 –0.82 (m, 6H).

[0024] S4: Under nitrogen protection, 500 ml of methanol, 0.1 mol of alkynyl compound and 0.42 mol of nicotinic acid azide formyl are added into a reaction kettle, stirred and mixed evenly, 60 ml of deionized aqueous solution containing 0.04 mol of copper sulfate and 0.08 mol of sodium ascorbate is added, stirred at room temperature for 20 h, 800 ml of tetrahydrofuran is added to stir and precipitate solids, filtered, washed with 500 ml of tetrahydrofuran, filtered, and vacuum dried at 50 °C for 12 h to obtain an antibacterial agent. The 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ 9.10 (t, J = 1.7 Hz, 4H), 8.74 (ddd, J = 4.8, 2.6, 1.6 Hz, 4H), 8.33 (ddd, J = 7.0, 2.6, 2.0 Hz, 4H), 8.29 (t, J = 0.8 Hz, 4H), 7.59 (dd, J = 6.9, 4.8 Hz, 4H), 3.86 - 3.78 (m, 12H), 3.73 (dtd, J = 6.2, 4.1, 0.7 Hz, 12H), 3.66 (s, 4H), 3.59 (t, J = 6.6 Hz, 8H), 3.46 (t, J = 8.7 Hz, 4H), 2.89 - 2.77 (m, 8H), 2.12 (tt, J = 8.5, 6.7 Hz, 8H), 1.70 (tt, J = 8.6, 6.2 Hz, 4H), 1.46 - 1.22 (m, 40H), 0.96 - 0.82 (m, 6H).

[0025] Example 2 Preparation of antibacterial agent: S1: 1000 ml of absolute ethanol and 1 mol of diethanolamine are added into a reaction kettle and stirred evenly. The temperature is raised to 75 °C, 1 mol of 1-chlorotridecane is added dropwise, and the addition is completed in 30 min. The reaction is refluxed for 46 h, 1.2 mol of potassium carbonate is added and the reaction continues for 4 h. It is cooled to room temperature, distilled under reduced pressure at 50 °C for 2 h, 1200 ml of ether is added to dissolve, washed with deionized water (500 ml × 3 times), the organic phase is dried with 100 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 30 °C for 2 h to obtain a tertiary amine compound; S2: Under nitrogen protection, add 500 ml of absolute ethanol and 0.2 mol of tertiary amine compound into the reaction kettle, stir and mix evenly, heat up to 70 °C, dropwise add 0.1 mol of 1,2-bis(2-chloroethoxy)ethane, finish dropping in 30 min, reflux and react for 48 h, cool to room temperature, carry out reduced pressure distillation at 40 °C for 2 h, add 500 ml of a mixed solution of ethyl acetate and absolute ethanol (volume ratio of ethyl acetate to absolute ethanol is 8:2) for recrystallization, stand still for 10 h under ice bath, filter, and carry out vacuum drying at 45 °C for 10 h to obtain the quaternary ammonium salt compound; S3: Add 600 ml of absolute DMF, 0.1 mol of quaternary ammonium salt compound and 0.5 mol of sodium hydroxide into the reaction kettle, stir for 30 min, add 0.42 mol of 5-chloro-1-pentyne, heat up to 80 °C, react for 8 h, cool to room temperature, filter, carry out reduced pressure distillation at 60 °C for 1 h, add 400 ml of methanol to precipitate solids, filter, wash with 400 ml of 80 wt% methanol aqueous solution, and carry out vacuum drying at 50 °C for 20 h to obtain the alkynyl compound; S4: Under nitrogen protection, add 500 ml of methanol, 0.1 mol of alkynyl compound and 0.45 mol of nicotinic acid formyl azide into the reaction kettle, stir and mix evenly, add 60 ml of deionized water solution containing 0.045 mol of copper sulfate and 0.12 mol of sodium ascorbate, stir at room temperature for 24 h, add 800 ml of tetrahydrofuran to stir and precipitate solids, filter, wash with 500 ml of tetrahydrofuran, filter, and carry out vacuum drying at 50 °C for 12 h to obtain the antibacterial agent.

[0026] Example 3 Preparation of antibacterial agent: S1: Add 1000 ml of absolute ethanol and 1 mol of diethanolamine into the reaction kettle, stir and mix evenly, heat up to 75 °C, dropwise add 1.1 mol of 1-chlorotridecane, finish dropping in 30 min, reflux and react for 48 h, add 1.2 mol of potassium carbonate and continue to react for 4 h, cool to room temperature, carry out reduced pressure distillation at 50 °C for 2 h, add 1200 ml of ether to dissolve, wash with deionized water (500 ml × 3 times), dry the organic phase with 100 g of anhydrous magnesium sulfate, filter, and carry out reduced pressure distillation at 30 °C for 2 h to obtain the tertiary amine compound; S2: Under nitrogen protection, add 500 ml of absolute ethanol and 0.2 mol of tertiary amine compound into the reaction kettle, stir and mix evenly, heat up to 70 °C, dropwise add 0.11 mol of 1,2-bis(2-chloroethoxy)ethane, finish dropping in 30 min, reflux and react for 50 h, cool to room temperature, carry out reduced pressure distillation at 40 °C for 2 h, add 500 ml of a mixed solution of ethyl acetate and absolute ethanol (volume ratio of ethyl acetate to absolute ethanol is 8:2) for recrystallization, stand still for 10 h under ice bath, filter, and carry out vacuum drying at 45 °C for 10 h to obtain the quaternary ammonium salt compound; S3: Add 600 ml of anhydrous DMF, 0.1 mol of quaternary ammonium salt compound, and 0.5 mol of sodium hydroxide into the reaction kettle, stir for 30 min, add 0.45 mol of 5-chloro-1-pentyne, heat up to 90 °C, react for 5 h, cool to room temperature, filter, distill under reduced pressure at 60 °C for 1 h, add 400 ml of methanol to precipitate solids, filter, wash with 400 ml of 80 wt% methanol aqueous solution, and dry in vacuum at 50 °C for 20 h to obtain the alkynyl compound; S4: Under nitrogen protection, add 500 ml of methanol, 0.1 mol of alkynyl compound, and 0.48 mol of nicotinic acid azide formyl into the reaction kettle, stir and mix evenly, add 60 ml of deionized aqueous solution containing 0.05 mol of copper sulfate and 0.16 mol of sodium ascorbate, stir at room temperature for 26 h, add 800 ml of tetrahydrofuran to stir and precipitate solids, filter, wash with 500 ml of tetrahydrofuran, filter, and dry in vacuum at 50 °C for 12 h to obtain the antibacterial agent.

[0027] Example 4 Preparation of Flame Retardant: N1: Under ice bath, add 2000 ml of methanol and 1 mol of 3-aminopropylmethyldimethoxysilane into the reaction kettle, under nitrogen protection, add 2 mol of [4-(vinyloxy)phenyl]methanol in batches (add in 8 batches, with an interval of 10 min between each batch), raise the temperature to room temperature and react for 12 h, distill under reduced pressure at 50 °C for 2 h to obtain the hydroxyl compound; The 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ 7.21 - 7.12 (m, 4H), 6.93 - 6.82 (m, 4H), 4.91 (t, J = 5.7 Hz, 2H), 4.59 (dt, J = 5.6, 0.9 Hz, 4H), 4.11 (t, J = 5.9 Hz, 4H), 3.43 (s, 6H), 2.93 (t, J = 5.9 Hz, 4H), 2.54 (d, J = 14.2 Hz, 2H), 1.55 - 1.38 (m, 2H), 0.85 - 0.73 (m, 2H), 0.13 (s, 3H).

[0028] N2: Under nitrogen protection, add 2000 ml of acetonitrile and 1 mol of hydroxyl compound into the reaction kettle, stir and mix evenly, heat up to 60 °C, dropwise add 0.8 mol of phenylphosphonic dichloride to react, finish dropping in 30 min, react for 10 h, cool to room temperature, filter by suction, wash successively with 1200 ml of acetonitrile and 1500 ml of deionized water, and dry in vacuum at 60 °C for 24 h to obtain the flame retardant.

[0029] Example 5 Preparation of Antibacterial Formaldehyde-Free Impregnating Adhesive (1) Weigh: 450 g of aqueous polyurethane dispersion, 5 g of defoamer (silicone defoamer), 20 g of wetting agent (sodium dodecyl sulfonate), 10 g of thickener (sodium carboxymethyl cellulose), 20 g of antibacterial agent (prepared in Example 1), 50 g of flame retardant (prepared in Example 4), and 300 g of deionized water; (2) Mix the aqueous polyurethane dispersion, deionized water, defoamer, and wetting agent, stir at 500 rpm for 10 min, add the antibacterial agent and flame retardant and stir, stir at 500 rpm for 10 min, add the thickener and stir, stir at 200 rpm for 30 min to obtain a formaldehyde-free impregnating adhesive.

[0030] Example 6 Preparation of Antibacterial Formaldehyde-Free Impregnating Adhesive (1) Weigh: 630 g of aqueous polyurethane dispersion, 8 g of defoamer (silicone defoamer), 28 g of wetting agent (fatty acid polyoxyethylene ether), 14 g of thickener (sodium carboxymethyl cellulose), 45 g of antibacterial agent (prepared in Example 2), 70 g of flame retardant (prepared in Example 4), and 450 g of deionized water; (2) Mix the aqueous polyurethane dispersion, deionized water, defoamer, and wetting agent, stir at 500 rpm for 10 min, add the antibacterial agent and flame retardant and stir, stir at 500 rpm for 10 min, add the thickener and stir, stir at 100 rpm for 30 min to obtain a formaldehyde-free impregnating adhesive.

[0031] Example 7 Preparation of Antibacterial Formaldehyde-Free Impregnating Adhesive (1) Weigh: 700 g of aqueous polyurethane dispersion, 10 g of defoamer (silicone defoamer), 30 g of wetting agent (fatty acid polyoxyethylene ether), 15 g of thickener (sodium carboxymethyl cellulose), 50 g of antibacterial agent (prepared in Example 3), 80 g of flame retardant (prepared in Example 4), and 500 g of deionized water; (2) Mix the aqueous polyurethane dispersion, deionized water, defoamer, and wetting agent, stir at 500 rpm for 10 min, add the antibacterial agent and flame retardant and stir, stir at 500 rpm for 10 min, add the thickener and stir, stir at 200 rpm for 30 min to obtain a formaldehyde-free impregnating adhesive.

[0032] Comparative Example 1 The raw material composition and process of the antibacterial formaldehyde-free impregnating adhesive are basically the same as those in Example 6, the difference is that the antibacterial agent (prepared in Example 2) added in the components is replaced with an equal mass of quaternary ammonium salt compound (prepared in step S2 of Example 2) as the antibacterial agent.

[0033] Comparative Example 2 The raw material composition and process of the antibacterial formaldehyde-free impregnating adhesive are basically the same as those in Example 6, the difference is that the antibacterial agent (prepared in Example 2) added in the components is replaced with an equal mass of antibacterial agent prepared by the following method: The preparation process of the antibacterial agent is basically the same as that of Example 2, except that the nicotinic acid formyl azide in step S4 is replaced with an equimolar amount of benzyl azide.

[0034] Comparative Example 3 The raw material composition and process of the antibacterial formaldehyde-free impregnating adhesive are basically the same as those of Example 6, except that the antibacterial agent added in the components (prepared in Example 2) is replaced with an antibacterial agent prepared by the following method with the same mass: S1: Add 1000 ml of absolute ethanol and 1 mol of diethanolamine into the reaction kettle, stir and mix evenly, heat up to 75 °C, dropwise add 1 mol of 1-chlorotridecane, finish dropping in 30 min, reflux and react for 46 h, add 1.2 mol of potassium carbonate and continue to react for 4 h, cool to room temperature, carry out vacuum distillation at 50 °C for 2 h, add 1200 ml of ether to dissolve, wash with deionized water (500 ml × 3 times), dry the organic phase with 100 g of anhydrous magnesium sulfate, filter, carry out vacuum distillation at 30 °C for 2 h to obtain a tertiary amine compound; S2: Add 600 ml of absolute DMF, 0.1 mol of the tertiary amine compound and 0.5 mol of sodium hydroxide into the reaction kettle, stir for 30 min, add 0.22 mol of 5-chloro-1-pentyne, heat up to 80 °C, react for 8 h, cool to room temperature, filter, carry out vacuum distillation at 60 °C for 1 h, add 400 ml of methanol to precipitate solids, filter, wash with 400 ml of 80 wt% methanol aqueous solution, repeat three times, and carry out vacuum drying at 50 °C for 20 h to obtain a diynyl compound; S3: Under nitrogen protection, add 500 ml of methanol, 0.1 mol of the diynyl compound and 0.25 mol of nicotinic acid formyl azide into the reaction kettle, stir and mix evenly, add 60 ml of a deionized water solution containing 0.025 mol of copper sulfate and 0.06 mol of sodium ascorbate, stir at room temperature for 24 h, add 800 ml of tetrahydrofuran to stir and precipitate solids, filter, wash with 500 ml of tetrahydrofuran, filter, and carry out vacuum drying at 50 °C for 12 h to obtain an antibacterial agent.

[0035] Comparative Example 4 The raw material composition and process of the antibacterial formaldehyde-free impregnating adhesive are basically the same as those of Example 6, except that the flame retardant added in the components (prepared in Example 4) is replaced with a substance prepared by mixing a hydroxy compound (prepared in step N1 of Example 4) and phenylphosphonic dichloride in a mass ratio of 1:3 with the same mass.

[0036] Comparative Example 5 The raw material composition and process of the antibacterial formaldehyde-free impregnating adhesive are basically the same as those of Example 6, except that the flame retardant added in the components (prepared in Example 4) is replaced with a flame retardant prepared by the following method with the same mass: The preparation process of the flame retardant is basically the same as that of Example 4, except that the addition amount of dichlorophenylphosphine in step N2 is replaced from 0.8 mol to 0.5 mol.

[0037] The grade of the aqueous polyurethane dispersion used in the examples and comparative examples of this application is Dispercoll® U54, with a solid content of 50 wt%; the grade of the silicone defoamer is Efka® SI 2722; the model of sodium carboxymethyl cellulose is HY-Y1889A, with a molecular weight of 250,000; the model of fatty alcohol polyoxyethylene ether is AEO-9.

[0038] The antibacterial formaldehyde-free impregnating adhesive prepared in Examples 5-7 and Comparative Examples 1-5 was used to impregnate the decorative base paper (Zhejiang Jiding New Material Technology Co., Ltd.: SC8001-1-85) for 5 minutes, and then placed in a blast drying oven at 90 °C. After drying for 45 minutes, the impregnated paper was taken out; the antibacterial formaldehyde-free impregnating adhesive was coated on the upper and lower surfaces of the impregnated paper (coating thickness 0.5 mm), and then placed in an oven at 90 °C and dried for another 45 minutes to obtain the artificial board decorative paper. In order to better test the antibacterial and antifungal properties, combustion performance and formaldehyde release performance of the impregnating adhesive, the artificial board decorative paper for testing was coated on both sides.

[0039] The formaldehyde release amount of the artificial board decorative paper was tested according to GB 18580-2017; the antibacterial and antifungal properties were tested according to JC / T 2039-2010; the flame retardant properties were tested according to GB / T 8624-2012, and the test results are shown in Table 1.

[0040]

[0041] From the data of Examples 5, 6, and 7 in Table 1, it can be seen that the antibacterial formaldehyde-free impregnating adhesive prepared by the present invention has excellent antibacterial and flame retardant properties, and no formaldehyde is released, meeting the requirements of environmental protection, safety and high performance.

[0042] In the antibacterial agent prepared in this application, the long-chain alkyl inserts into the bacterial cell membrane through hydrophobic interaction, destroying the membrane integrity; at the same time, the positively charged quaternary ammonium salt binds to the negative charge on the bacterial surface, resulting in a change in the cell membrane permeability and interfering with the normal metabolic activities of the cell. The ether bond (-O-) in the antibacterial agent can enhance the binding force with the polyurethane matrix through hydrogen bond interaction, improve the migration resistance, and ensure the long-term action of the antibacterial agent. The triazole structure can form specific interactions with bacterial target proteins through hydrogen bonds, inhibit the activity of key enzymes, and play an antibacterial role. The pyridine structure can bind to the nucleic acid in the bacterial cell, interfering with its normal replication and transcription processes, thereby inhibiting the reproduction of bacteria; and the aromaticity of the pyridine ring and the presence of nitrogen atoms endow it with good chemical stability, and at the same time can also improve the solubility of the antibacterial agent and the cell membrane penetration ability.

[0043] The flame retardant prepared in this application can achieve efficient flame retardancy through multi-path synergy: in the condensed phase, the phosphorus in the flame retardant decomposes when heated to produce strong dehydrating agents such as polyphosphoric acid, which promotes rapid dehydration and carbonization of the material surface to form a carbon layer, isolating oxygen and heat sources; in the gas phase, the PO· free radicals generated by the decomposition of phosphorus in the flame retardant can capture the H· and OH· free radicals generated by combustion, inhibiting the combustion process. When the nitrogen element in the flame retardant burns, the generated nitrogen-containing inert gas can dilute the concentration of combustible gases such as oxygen, and at the same time the decomposition process can reduce the surface temperature of the material. The silicon atoms in this flame retardant will migrate to the polymer surface at high temperature to form a silicate protective layer, blocking the transfer of heat and oxygen, and at the same time promoting the formation of a carbon layer on the material surface, improving the thermal stability. The flame retardant used in Comparative Example 4 contains a large amount of chlorine element, and toxic gases such as dioxin and hydrogen chloride will be released during combustion, endangering personal safety.

[0044] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; however, for those of ordinary skill in the art, without departing from the scope of the technical solution of the present invention, any slight changes, modifications and equivalent changes evolved by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An antibacterial formaldehyde-free impregnating adhesive, characterized in that, It comprises raw materials in the following parts by weight: 45 - 70 parts of aqueous polyurethane dispersion, 0.5 - 1 part of defoamer, 2 - 3 parts of wetting agent, 1 - 1.5 parts of thickener, 2 - 5 parts of antibacterial agent, 5 - 8 parts of flame retardant, 30 - 50 parts of deionized water; The antibacterial agent is prepared by reacting diethanolamine with 1 - chlorotridecane to form a tertiary amine compound, then reacting with 1,2 - bis(2 - chloroethoxy)ethane to form a quaternary ammonium salt compound, then reacting with 5 - chloro - 1 - pentyne to form an alkynyl compound, and finally reacting with nicotinic acid azide formyl.

2. The antibacterial formaldehyde-free impregnating adhesive according to claim 1, wherein The antibacterial agent is prepared by the following method: S1: Diethanolamine reacts with 1 - chlorotridecane under the action of potassium carbonate to form a tertiary amine compound; S2: The tertiary amine compound reacts with 1,2 - bis(2 - chloroethoxy)ethane to form a quaternary ammonium salt compound; S3: The quaternary ammonium salt compound reacts with 5 - chloro - 1 - pentyne under the action of sodium hydroxide to form an alkynyl compound; S4: The alkynyl compound reacts with nicotinic acid azide formyl under the action of catalyst copper sulfate and reducing agent sodium ascorbate to obtain the antibacterial agent.

3. The antibacterial formaldehyde-free impregnating adhesive according to claim 2, wherein In the step S1, the feeding molar ratio of diethanolamine to 1 - chlorotridecane is 1:(0.8 - 1.1).

4. The antibacterial formaldehyde-free impregnating adhesive according to claim 2, wherein In the step S2, the feeding molar ratio of the tertiary amine compound to 1,2 - bis(2 - chloroethoxy)ethane is 2:(0.9 - 1.1).

5. An antibacterial formaldehyde-free impregnating adhesive according to claim 2, characterized in that, In the step S3, the feeding molar ratio of the quaternary ammonium salt compound to 5 - chloro - 1 - pentyne is 1:(4 - 4.5).

6. An antibacterial formaldehyde-free impregnating adhesive according to claim 2, characterized in that, In the step S4, the feeding molar ratio of the alkynyl compound to nicotinic acid azide formyl is 1:(4.2 - 4.8).

7. An antibacterial formaldehyde-free impregnating adhesive according to claim 1, wherein, The flame retardant is prepared by the following method: N1: 3 - aminopropylmethyldimethoxysilane reacts with [4 - (vinyloxy)phenyl]methanol to form a hydroxyl compound; N2: The hydroxyl compound reacts with phenylphosphonic dichloride to form the flame retardant.

8. An antibacterial formaldehyde-free impregnating adhesive according to claim 7, characterized in that, In the step N1, the feeding molar ratio of 3 - aminopropylmethyldimethoxysilane to [4 - (vinyloxy)phenyl]methanol is 1:2; in the step N2, the feeding molar ratio of the hydroxyl compound to phenylphosphonic dichloride is 1:0.

8.

9. An antibacterial formaldehyde-free impregnating adhesive according to claim 1, wherein, The defoamer is an organosilicon defoamer; the wetting agent is one of sodium dodecyl sulfonate and fatty acid polyoxyethylene ether; the thickener is sodium carboxymethyl cellulose.

10. The preparation process of the antibacterial and formaldehyde-free impregnating adhesive according to any one of claims 1-9, characterized in that, It comprises the following steps: (1) Weigh by parts by weight: 45 - 70 parts of aqueous polyurethane dispersion, 0.5 - 1 part of defoamer, 2 - 3 parts of wetting agent, 1 - 1.5 parts of thickener, 2 - 5 parts of antibacterial agent, 5 - 8 parts of flame retardant, 30 - 50 parts of deionized water; (2) Stir the aqueous polyurethane dispersion, deionized water, defoamer, and wetting agent evenly, add the antibacterial agent and flame retardant and stir evenly, then add the thickener and stir evenly to obtain the formaldehyde - free impregnating adhesive.

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