CN117720704A

CN117720704A - Aqueous polyurethane emulsion and preparation method and application thereof

Info

Publication number: CN117720704A
Application number: CN202410139950.6A
Authority: CN
Inventors: 王维明; 钱能; 钱国春; 董爱学; 孟金贵; 漏秀文
Original assignee: Zhejiang Meisheng New Materials Co ltd
Current assignee: Zhejiang Meisheng New Materials Co ltd
Priority date: 2024-02-01
Filing date: 2024-02-01
Publication date: 2024-03-19
Anticipated expiration: 2044-02-01
Also published as: CN117720704B

Abstract

The invention belongs to the technical field of polyurethane, and provides a waterborne polyurethane emulsion, a preparation method and application thereof. The method comprises the following steps: mixing polymer dihydric alcohol with diisocyanate to react to obtain a mixture a; mixing the mixture a, dibutyl tin dilaurate and N, N-dimethylformamide for reaction to obtain a mixture b; mixing the mixture b, a chain extender and DMF for reaction to obtain a mixture c; mixing the mixture c, a haloamine antibacterial monomer, an ultraviolet absorber and DMF for reaction to obtain a mixture d; mixing the mixture d, an antioxidant, triethylamine and DMF for reaction to obtain a mixture e; and mixing the DMF solution of the mixture e, water and diethylenetriamine for emulsification to obtain the aqueous polyurethane emulsion. The invention has simple process and controllable conditions, and the obtained polyurethane film has lasting bacteriostasis, good bacteriostasis and reproducibility and bacteriostasis and illumination resistance.

Description

Aqueous polyurethane emulsion and preparation method and application thereof

Technical Field

The invention relates to the technical field of polyurethane, in particular to aqueous polyurethane emulsion and a preparation method and application thereof.

Background

Synthetic leather is generally a simulated leather product which is prepared by using non-woven fabrics as a base material, adopting polyurethane or polyvinyl chloride to coat the surface, and processing the film. Among them, polyurethane synthetic leather is widely used in the fields of shoes, furniture, clothing, luggage, automobile interior trim and the like due to its excellent properties of wear resistance, folding resistance, waterproof and moisture permeability, weather resistance and the like, and becomes the best choice for replacing natural leather. However, these leather products are in close contact with the human body, so that sweat and sebum containing metabolites are easily absorbed from sweat of the skin, and a nutrition source is provided for the derivative propagation of bacteria, which not only generates unpleasant odor, reduces the application performance (such as discoloration, mechanical strength reduction and the like) of the product, but also threatens the health and life safety of the human body (such as skin diseases, diseases induced in the human body, and the like). Therefore, the antibacterial material is added to endow the synthetic leather with antibacterial and bactericidal functions, so that the synthetic leather has important application value and wide market prospect.

The haloamine antibacterial agent is an antibacterial agent containing one or more N-X structures (X is halogen such as Cl, br and the like) in a molecular structure, and is a renewable antibacterial agent prepared by reacting a compound containing amine, amide or imide groups with hypohalite. The molecular structure of the halamine compound can introduce active groups such as double bonds (C=C) (such as ADMH, VBDMH and the like), hydroxyl groups (-OH) (such as MDMH and the like), silicon hydroxyl groups (Si-OH) (such as DTH and the like) and the like, and the bonding strength of the antibacterial agent and the matrix is improved through valence bond bonding, so that the antibacterial durability of the grafted modified material is improved. Haloamine antibacterial agents are a research hotspot for antibacterial materials due to their high efficacy, broad spectrum and low liability to variability. For example: chinese patent CN111893642A discloses a halamine polymer antibacterial antiviral nanofiber membrane, which is prepared by blending tetraalkylpiperidinol grafted polyacrylic acid polymer with polyurethane solution, and adopting electrostatic spinning to prepare a nanofiber membrane with a certain affinity/oleophobic polymer interpenetrating network structure; chinese patent CN116288929A and Chinese journal "halamine compound modified polyurethane nanofiber membrane structure and antibacterial property" (Yang Shiyu, yan Kelu, wang Weiming. Halamine compound modified polyurethane nanofiber membrane structure and antibacterial property [ J ]. Printing and dyeing, 2023,49 (07): 1-6.) all take 1-hydroxymethyl-5, 5-dimethylhydantoin (MDMH) as monomers, graft into the structure in the polyurethane synthesis process, and then make into nanofiber membrane through electrostatic spinning. However, the tetraalkylpiperidinol monomer and the MDMH have only one hydroxyl group in the molecular structure, so that the linear polyurethane molecular chain is easy to carry out end-capping and termination reaction, the polyurethane molecular weight is difficult to control, the molecular weight distribution is wider, and the performance of the nanofiber membrane is easy to influence. The invention patent CN115045006A discloses a preparation method of polyurethane nanofiber material for air purification, which comprises the steps of firstly pre-polymerizing polycaprolactone and methylene diphenyl diisocyanate, then utilizing two hydroxyl (-OH) groups in imidazolidinyl urea to participate in the polymerization reaction of polyurethane, then mixing the imidazolidinyl urea modified polyurethane with common polyurethane, and then preparing the antibacterial nanofiber through electrostatic spinning. Although this method solves the influence of the antibacterial monomer on the molecular weight of polyurethane, it is relatively expensive. In addition, the instability of N-Cl bond in N-Cl haloamine under 315-400 nm long-wave ultraviolet light can lead to the rapid reduction of active chlorine content in a short time, so that the antibacterial performance of the material is rapidly reduced. Therefore, it is of great importance to provide a modified polyurethane which has lasting antibacterial property and antibacterial reproducibility without affecting the molecular weight of the polyurethane.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provides a waterborne polyurethane emulsion, a preparation method and application thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of aqueous polyurethane emulsion, which comprises the following steps:

(1) Mixing polymer dihydric alcohol with diisocyanate to react to obtain a mixture a;

(2) Mixing the mixture a, dibutyl tin dilaurate and N, N-dimethylformamide for reaction to obtain a mixture b;

(3) Mixing the mixture b, a chain extender and N, N-dimethylformamide for reaction to obtain a mixture c;

(4) Mixing the mixture c, a haloamine antibacterial monomer, an ultraviolet absorber and N, N-dimethylformamide for reaction to obtain a mixture d;

(5) Mixing the mixture d, an antioxidant, triethylamine and N, N-dimethylformamide for neutralization reaction to obtain a mixture e;

(6) Mixing and emulsifying the N, N-dimethylformamide solution, water and diethylenetriamine of the mixture e to obtain the aqueous polyurethane emulsion;

the halamine antibacterial monomer in the step (4) is 3- (2, 3-dihydroxypropyl) -5, 5-dimethyl hydantoin, and the structural formula of the 3- (2, 3-dihydroxypropyl) -5, 5-dimethyl hydantoin is as follows:

。

preferably, the mass ratio of the polymer diol to the diisocyanate in the step (1) is 30-40: 15-20 parts of a base;

the reaction temperature in the step (1) is 60-65 ℃ and the reaction time is 60-90 min.

Preferably, the mass volume ratio of the polymer dihydric alcohol in the step (1) to the dibutyl tin dilaurate and the N, N-dimethylformamide in the step (2) is 30-40 g: 0.1-0.3 g: 10-20 mL;

the temperature of the reaction in the step (2) is 70-75 ℃ and the time is 90-120 min.

Preferably, the mass-volume ratio of the polymer diol in the step (1) to the chain extender in the step (3) to the N, N-dimethylformamide is 30-40 g: 5-10 g: 15-20 mL;

the temperature of the reaction in the step (3) is 80-90 ℃ and the time is 30-45 min.

Preferably, the ultraviolet absorber in the step (4) is 2, 4-dihydroxybenzophenone;

the mass volume ratio of the polymer dihydric alcohol in the step (1) to the haloamine antibacterial monomer, the ultraviolet absorber and the N, N-dimethylformamide in the step (4) is 30-40 g: 1-3 g: 2-5 g: 15-25 mL;

and (3) the reaction temperature in the step (4) is 80-90 ℃ and the reaction time is 60-90 min.

Preferably, the antioxidant in the step (5) is pentaerythritol tetra (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate);

the mass volume ratio of the polymer dihydric alcohol in the step (1) to the antioxidant, triethylamine and N, N-dimethylformamide in the step (5) is 30-40 g: 0.01-0.1 g: 3-5 g: 5-15 mL;

and (5) the neutralization reaction temperature is 50-60 ℃ and the neutralization reaction time is 30-60 min.

Preferably, the viscosity of the N, N-dimethylformamide solution of the mixture e in the step (6) is 7000-8000 Pa/s;

the mass volume ratio of the polymer dihydric alcohol in the step (1) to the water and diethylenetriamine in the step (6) is 30-40 g: 200-300 mL:0.5 to 1.0mL;

and (3) emulsifying at the temperature of 20-30 ℃ for 60-90 min.

The invention also provides the aqueous polyurethane emulsion obtained by the preparation method.

The invention also provides application of the aqueous polyurethane emulsion in synthetic leather products.

The beneficial effects of the invention are as follows:

the invention provides a preparation method of aqueous polyurethane emulsion, which comprises the following steps: mixing polymer dihydric alcohol with diisocyanate to react to obtain a mixture a; mixing the mixture a, dibutyl tin dilaurate and N, N-dimethylformamide for reaction to obtain a mixture b; mixing the mixture b, a chain extender and N, N-dimethylformamide for reaction to obtain a mixture c; mixing the mixture c, a haloamine antibacterial monomer, an ultraviolet absorber and N, N-dimethylformamide for reaction to obtain a mixture d; mixing the mixture d, an antioxidant, triethylamine and N, N-dimethylformamide for neutralization reaction to obtain a mixture e; and mixing the N, N-dimethylformamide solution of the mixture e, water and diethylenetriamine for emulsification to obtain the aqueous polyurethane emulsion. The invention has simple process and controllable conditions, and the reaction is basically carried out under the medium and low temperature condition of below 100 ℃. The haloamine antibacterial monomer contains an N-H bond, the haloamine antibacterial agent is obtained after hypohalite action, and the molecular structure of the haloamine antibacterial agent contains an N-X bond (wherein X is halogen) and can be repeatedly dehalogenated and halogenated, so that a film formed by coating the aqueous polyurethane emulsion prepared by the invention has good antibacterial reproducibility; in addition, the haloamine antibacterial monomer structure does not contain alpha hydrogen, and the ultraviolet absorber is simultaneously connected into the polyurethane structure, so that the stability of N-X bonds after halogenation is improved, and the film has lasting antibacterial performance; meanwhile, the introduction of the ultraviolet absorber also weakens the influence of ultraviolet in sunlight on the stability of N-X bonds in the antibacterial agent, so that the film formed by coating the aqueous polyurethane emulsion has good antibacterial and light-resistant properties.

Drawings

FIG. 1 is a schematic illustration of the dehalogenation and halogenation process of a haloamine antimicrobial monomer according to the present invention.

Detailed Description

。

in the present invention, the N, N-dimethylformamide may be labeled DMF.

In the present invention, the preparation method of 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin preferably comprises the following steps:

mixing 5, 5-dimethyl hydantoin, water, sodium hydroxide and 3-chloroglycerol, and reacting to obtain the 3- (2, 3-dihydroxypropyl) -5, 5-dimethyl hydantoin.

In the invention, the molar volume ratio of the 5, 5-dimethyl hydantoin, water, sodium hydroxide and 3-chloroglycerol is preferably 0.005-0.015 mol: 90-110 mL:0.015 to 0.025mol:0.005 to 0.015mol, more preferably 0.007 to 0.013mol: 95-105 mL:0.017 to 0.023mol:0.007 to 0.013mol, more preferably 0.009 to 0.010mol: 97-100 mL:0.018 to 0.020mol: 0.009-0.010mol.

In the present invention, the mixing preferably comprises the steps of:

(a) Mixing 3-chloroglycerol with a first portion of water to obtain a 3-chloroglycerol solution;

(b) Mixing 5, 5-dimethyl hydantoin, residual water and sodium hydroxide to obtain a mixed solution;

(c) The 3-chloroglycerol solution was slowly added dropwise to the mixed solution to complete the mixing.

In the present invention, the volume ratio of the first portion of water in the step (a) to the remaining water in the step (b) is preferably 45 to 55:45 to 55, more preferably 47 to 53:47 to 53, more preferably 50 to 51: 50-51.

In the invention, the reaction temperature is preferably 20-30 ℃, more preferably 22-28 ℃, and even more preferably 25-26 ℃; the reaction time is preferably 10 to 14 hours, more preferably 11 to 13 hours, and even more preferably 12 to 12.5 hours.

In the invention, after the reaction is finished, the pH value of the system is regulated by sulfuric acid solution, then rotary evaporation is carried out to remove water, the obtained solid is dissolved in N, N-dimethylformamide, filtration is carried out to remove sodium chloride which is a byproduct of the reaction, and finally reduced pressure distillation is carried out to remove N, N-dimethylformamide in the filtrate, thus obtaining the 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin.

In the invention, the mass fraction of the sulfuric acid solution is preferably 1-2%, more preferably 1.2-1.8%, and even more preferably 1.5-1.6%; the pH value of the system is regulated by sulfuric acid solution, and the target pH value is preferably 5.5-6.5, more preferably 5.7-6.3, and even more preferably 6-6.1; the temperature of the rotary steaming is preferably 35-40 ℃, more preferably 36-39 ℃, and even more preferably 37-38 ℃; the molar volume ratio of the N, N-dimethylformamide to the 5, 5-dimethylhydantoin is preferably 8-12 mL:0.005 to 0.015mol, more preferably 9 to 11mL:0.007 to 0.013mol, more preferably 10 to 10.5mL: 0.009-0.01 mol; the temperature of the reduced pressure distillation is preferably 50 to 60 ℃, more preferably 52 to 58 ℃, and even more preferably 55 to 56 ℃.

In the invention, the haloamine antibacterial monomer contains N-H bond, the haloamine antibacterial agent is obtained after hypohalite action, and the molecular structure of the haloamine antibacterial agent contains N-X bond (wherein X is halogen) which can be dehalogenated and halogenated repeatedly, so that the film formed by coating the aqueous polyurethane emulsion prepared by the invention has good antibacterial reproducibility; the dehalogenation and halogenation process of the haloamine antibacterial monomer are schematically shown in FIG. 1; the N-H bond generates N-Cl under the action of sodium hypochlorite (NaClO), and the N-Cl is hydrolyzed to release Cl under the action of water ⁺ N-H is generated simultaneously.

In the present invention, the polymer diol of step (1) preferably comprises polycaprolactone polyol and/or polyester diol PBA2000; when the polymer diol comprises a polycaprolactone polyol and a polyester diol, the mass ratio of the polycaprolactone polyol to the polyester diol is preferably 1:1.5 to 2.5, more preferably 1:1.7 to 2.3, more preferably 1: 2-2.1.

In the present invention, the polymer diol in step (1) is preferably dehydrated before being mixed, and the vacuum degree of the dehydration is preferably 9 to 11kpa, more preferably 9.5 to 10.5kpa, and even more preferably 10 to 10.2kpa; the temperature is preferably 70-90 ℃, more preferably 75-85 ℃, and still more preferably 80-82 ℃; the time is preferably 1 to 2 hours, more preferably 1.2 to 1.8 hours, and still more preferably 1.3 to 1.5 hours.

In the present invention, the diisocyanate of step (1) preferably comprises one or more of isophorone diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate; when the diisocyanate comprises dicyclohexylmethane diisocyanate and isophorone diisocyanate, the mass ratio of dicyclohexylmethane diisocyanate to isophorone diisocyanate is preferably 2.5 to 3.5:1, more preferably 2.7 to 3.3:1, more preferably 3 to 3.1:1.

in the invention, the mass ratio of the polymer diol to the diisocyanate in the step (1) is preferably 30-40: 15-20, more preferably 32-38: 16 to 19, more preferably 35 to 36: 17-18.

In the present invention, the temperature of the mixing in the step (1) is preferably 45 to 55 ℃, more preferably 47 to 53 ℃, and even more preferably 50 to 51 ℃.

In the invention, the temperature of the reaction in the step (1) is preferably 60-65 ℃, more preferably 61-64 ℃, and even more preferably 62-63 ℃; the time is preferably 60 to 90 minutes, more preferably 65 to 85 minutes, and even more preferably 70 to 80 minutes.

In the invention, the mass-volume ratio of the polymer dihydric alcohol in the step (1) to the dibutyl tin dilaurate and the N, N-dimethylformamide in the step (2) is preferably 30-40 g: 0.1-0.3 g:10 to 20mL, more preferably 32 to 38g: 0.15-0.25 g: 12-18 mL, more preferably 35-36 g: 0.2-0.23 g: 15-16 mL.

In the present invention, the mixing in step (2) is preferably: and (2) initially mixing dibutyltin dilaurate with the mixture a at the reaction temperature of the step (1), adding N, N-dimethylformamide into a mixed system consisting of the mixture a and dibutyltin dilaurate in batches and in equal amounts in the process of raising the reaction temperature of the step (1) to the reaction temperature of the step (2), completing the mixing, and then carrying out the reaction of the step (2).

In the present invention, the number of batch times is preferably 2 to 5 times, more preferably 3 to 4 times.

In the invention, the temperature of the reaction in the step (2) is preferably 70-75 ℃, more preferably 71-74 ℃, and even more preferably 72-73 ℃; the time is preferably 90 to 120 minutes, more preferably 95 to 115 minutes, and even more preferably 100 to 110 minutes.

In the present invention, the chain extender of step (3) preferably comprises one or more of ethylene glycol, 1, 4-butanediol, hydroquinone dihydroxyethyl ether and resorcinol dihydroxyethyl ether (CAS number 102-40-9).

In the invention, the mass-volume ratio of the polymer dihydric alcohol in the step (1) to the chain extender in the step (3) and the N, N-dimethylformamide is preferably 30-40 g: 5-10 g: 15-20 mL, more preferably 32-38 g: 6-9 g:16 to 19mL, more preferably 35 to 36g: 7-8 g: 17-18 mL.

In the present invention, the temperature of the mixing in the step (3) is preferably 70 to 75 ℃, more preferably 71 to 74 ℃, and even more preferably 72 to 73 ℃.

In the invention, the temperature of the reaction in the step (3) is preferably 80-90 ℃, more preferably 82-88 ℃, and even more preferably 85-86 ℃; the time is preferably 30 to 45 minutes, more preferably 35 to 40 minutes, and even more preferably 36 to 38 minutes.

In the present invention, the ultraviolet absorber in step (4) is preferably 2, 4-dihydroxybenzophenone, and the structural formula of the 2, 4-dihydroxybenzophenone is:。

in the invention, the mass-volume ratio of the polymer dihydric alcohol in the step (1) to the haloamine antibacterial monomer, the ultraviolet absorber and the N, N-dimethylformamide in the step (4) is preferably 30-40 g: 1-3 g: 2-5 g: 15-25 mL, more preferably 32-38 g: 1.5-2.5 g: 3-4 g: 17-23 mL, more preferably 35-36 g: 2-2.3 g: 3.5-3.6 g: 20-22 mL.

In the present invention, the temperature of the mixing in the step (4) is preferably 80 to 90 ℃, more preferably 82 to 88 ℃, and even more preferably 85 to 86 ℃.

In the invention, the temperature of the reaction in the step (4) is preferably 80-90 ℃, more preferably 82-88 ℃, and even more preferably 85-86 ℃; the time is preferably 60 to 90 minutes, more preferably 70 to 80 minutes, and even more preferably 73 to 75 minutes.

In the present invention, the antioxidant of step (5) is preferably pentaerythritol tetrakis (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate) (CAS No. 6683-19-8); the mass volume ratio of the polymer dihydric alcohol in the step (1) to the antioxidant, triethylamine and N, N-dimethylformamide in the step (5) is preferably 30-40 g: 0.01-0.1 g: 3-5 g: 5-15 mL, more preferably 32-38 g:0.03 to 0.07g: 3.5-4.5 g: 7-13 mL, more preferably 35-36 g: 0.05-0.06 g: 4-4.2 g: 10-11 mL.

In the present invention, the temperature of the mixing in the step (5) is preferably 50 to 60 ℃, more preferably 52 to 58 ℃, and even more preferably 55 to 56 ℃.

In the invention, the temperature of the neutralization reaction in the step (5) is preferably 50-60 ℃, more preferably 52-58 ℃, and even more preferably 55-56 ℃; the time is preferably 30 to 60 minutes, more preferably 40 to 55 minutes, and even more preferably 45 to 50 minutes.

In the present invention, the preparation method of the N, N-dimethylformamide solution of the mixture e in the step (6) is preferably to mix the mixture e with N, N-dimethylformamide to obtain the N, N-dimethylformamide solution of the mixture e.

In the present invention, N, N-dimethylformamide is used for adjusting the viscosity of the reaction system, and the viscosity of the N, N-dimethylformamide solution of the mixture e in the step (6) is preferably 7000 to 8000Pa/s, more preferably 7200 to 7800Pa/s, still more preferably 7500 to 7600Pa/s.

In the invention, the mass-volume ratio of the polymer diol in the step (1) to the water and diethylenetriamine in the step (6) is preferably 30-40 g: 200-300 mL:0.5 to 1.0mL, more preferably 32 to 38g: 220-280 mL:0.6 to 0.9mL, more preferably 35 to 36g: 250-260 mL: 0.7-0.8 mL.

In the present invention, the mixing in step (6) is preferably performed by slowly adding the first part of water into the N, N-dimethylformamide solution of the mixture e under stirring, rapidly adding the remaining water after successful phase inversion, and finally adding diethylenetriamine for emulsification.

In the present invention, the temperature of the first portion of water in the step (6) is preferably 3 to 7 ℃, more preferably 4 to 6 ℃, and even more preferably 5 to 5.5 ℃.

In the invention, the rotation speed of stirring is preferably 1200-1200 r/min, more preferably 1300-1700 r/min, and even more preferably 1500-160 r/min; the volume ratio of the first part of water to the residual water is preferably 70-100: 100 to 230, more preferably 75 to 95:120 to 200, more preferably 80 to 90: 150-160.

In the invention, the temperature of the emulsification in the step (6) is preferably 20-30 ℃, more preferably 22-28 ℃, and even more preferably 25-26 ℃; the time is preferably 60 to 90 minutes, more preferably 70 to 80 minutes, and even more preferably 73 to 75 minutes.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

Example 1

Mixing 0.01mol of 3-chloroglycerol with 50mL of water to obtain a 3-chloroglycerol solution; mixing 0.01mol of 5, 5-dimethyl hydantoin, 50mL of water and 0.02mol of sodium hydroxide to obtain a mixed solution; slowly dripping 3-chloroglycerol solution into the mixed solution, reacting for 12 hours at 25 ℃, after the reaction is finished, regulating the pH value of the system to 6 by using sulfuric acid solution with the mass fraction of 1.5%, then performing rotary evaporation at 37 ℃ to remove water, dissolving the obtained solid into 10mL of N, N-dimethylformamide, filtering to remove sodium chloride as a reaction byproduct, and finally performing reduced pressure distillation at 55 ℃ to remove N, N-dimethylformamide in the filtrate to obtain 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin;

30g of polymer diol (the polymer diol comprises polycaprolactone polyol and polyester diol PBA2000, the mass ratio of the polycaprolactone polyol to the polyester diol PBA2000 is 1:2) is dehydrated for 2 hours under the conditions of 10kpa of vacuum degree and 80 ℃, then the temperature is reduced to 50 ℃,20 g of diisocyanate (the diisocyanate comprises dicyclohexylmethane diisocyanate and isophorone diisocyanate, the mass ratio of dicyclohexylmethane diisocyanate to isophorone diisocyanate is 3:1) is added, the temperature is raised to 60 ℃, and the reaction is carried out for 60 minutes, thus obtaining a mixture a; mixing the mixture a with 0.2g of dibutyltin dilaurate at the temperature of 60 ℃, then heating to 70 ℃, adding 15mL of N, N-dimethylformamide (the volume of each addition is 5 mL) in 3 times in the heating process, completing mixing, and reacting for 90min at 70 ℃ to obtain a mixture b; mixing the mixture b with 8g of 1, 4-butanediol and 18mL of N, N-dimethylformamide at the temperature of 70 ℃, heating to 80 ℃, and reacting for 40min to obtain a mixture c; mixing the mixture c with 2g of 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin, 3g of 2, 4-dihydroxybenzophenone and 20mL of N, N-dimethylformamide at the temperature of 80 ℃ and reacting for 60min at the temperature of 80 ℃ to obtain a mixture d; mixing the mixture d with 0.06g of pentaerythritol tetra (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate), 3g of triethylamine and 10mL of N, N-dimethylformamide at 55 ℃ and carrying out neutralization reaction for 45min to obtain a mixture e; mixing the mixture e with N, N-dimethylformamide to obtain an N, N-dimethylformamide solution of the mixture e with the viscosity of 7000Pa/s, slowly adding 80mL of water with the temperature of 5 ℃ under the condition of stirring rotation speed of 1500r/min, rapidly adding the rest 150mL of water after phase inversion is successful, finally adding 0.8mL of diethylenetriamine, and emulsifying for 90min at 25 ℃ to obtain the aqueous polyurethane emulsion.

Comparative example 1

The other conditions in example 1 were controlled to be unchanged, the reaction time of the mixture b with 1, 4-butanediol, N-dimethylformamide was set to 90min, and the procedure of mixing and reacting the mixture c with 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin, 2, 4-dihydroxybenzophenone, N-dimethylformamide to obtain a mixture d was omitted without adding a haloamine antibacterial monomer (3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin) and an ultraviolet absorber (2, 4-dihydroxybenzophenone).

Comparative example 2

The other conditions in example 1 were controlled to be unchanged, and an ultraviolet absorber (2, 4-dihydroxybenzophenone) was not added to obtain an aqueous polyurethane emulsion.

Comparative example 3

The other conditions in example 1 were controlled to be unchanged, and the viscosity of the N, N-dimethylformamide solution of the mixture e was set to 8500mPa/s to obtain an aqueous polyurethane emulsion.

And (3) performing performance test on the aqueous polyurethane emulsion prepared in the embodiment 1 and the comparative examples 1-3, uniformly spreading the aqueous polyurethane emulsion prepared in the embodiment 1 and the comparative examples 1-3 on a polytetrafluoroethylene plate respectively, casting to form a film, drying at room temperature, and finally drying in a 70 ℃ oven for 10 hours to obtain a polyurethane coating film, wherein the film thickness is controlled to be 0.16+/-0.05 mm. Wherein, the bacteriostasis rate is evaluated according to GB/T20944.1-2007, the antibacterial property of textiles, part 1: the agar plate diffusion method is used for testing according to standard regulations; the washing method during the wash fastness test is as follows: preparing 2g/L of washing liquid by using a phosphorus-free ECE standard synthetic detergent, immersing a sample in the washing liquid, immersing in a water bath at 25+/-3 ℃ for 10min, fully cleaning with distilled water, airing, and recording as washing once; the method for testing the illumination resistance comprises the following steps: under the condition of simulating SUN illumination, the film is irradiated by adopting a Q-SUN-Xe-2-HS type light fastness instrument, and then the antibacterial rate of the film before and after irradiation is analyzed. The halogenation method during the regeneration performance test is as follows: at room temperature, immersing the polyurethane coating in a sodium hypochlorite solution with an effective chlorine content of 3000ppm for 30min, taking out after the treatment is finished, washing with water and drying. The results of comparing the performances of the aqueous polyurethane emulsions obtained in example 1 and comparative examples 1 to 3 are shown in Table 1.

Table 1 results of comparison of the properties of the aqueous polyurethane emulsions obtained in example 1 and comparative examples 1 to 3

Remarks: "-" means that no significant bacteriostatic effect is seen; "/" indicates unmeasured.

As can be seen from the data in table 1, the polyurethane film (comparative example 1) obtained from the aqueous polyurethane emulsion without the haloamine antibacterial monomer had no remarkable antibacterial effect, and the polyurethane films (examples 1 and comparative example 2) with the haloamine antibacterial monomer had a good antibacterial effect and had good wash fastness. As can be seen from comparative examples 1 and 2, the ultraviolet absorber has no significant effect on the antibacterial property of the halamine-modified polyurethane film and its wash resistance, but can significantly improve the light resistance of the antibacterial property of the polyurethane film. In addition, as can be seen from comparative examples 1 and 3, the viscosity of the polymer has a significant effect on the emulsifying property, and the viscosity is too large to successfully emulsify; while the low viscosity is favorable for emulsification, the dosage of the organic solvent is large, and the burden and cost for removing the organic solvent later are increased. In addition, the polyurethane film prepared in example 1 was subjected to an antibacterial reproducibility test, and the data in the table show that the halamine monomer modified polyurethane has good antibacterial reproducibility.

Example 2

3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin was prepared in the same manner as in example 1;

dehydrating 32g of polymer diol (the polymer diol comprises polycaprolactone polyol and polyester diol PBA2000, the mass ratio of the polycaprolactone polyol to the polyester diol PBA2000 is 1:2.3) for 1.5 hours under the conditions of 10.2kpa of vacuum degree and 85 ℃ of temperature, then cooling to 53 ℃, adding 18g of diisocyanate (the diisocyanate comprises dicyclohexylmethane diisocyanate and isophorone diisocyanate, the mass ratio of dicyclohexylmethane diisocyanate to isophorone diisocyanate is 3.1:1), heating to 63 ℃, and reacting for 65 minutes to obtain a mixture a; mixing the mixture a with 0.23g of dibutyltin dilaurate at the temperature of 63 ℃, then heating to 72 ℃, adding 18mL of N, N-dimethylformamide (the volume of each addition is 6 mL) in 3 times in the heating process, completing mixing, and reacting for 95min at 72 ℃ to obtain a mixture b; mixing the mixture b with 9g of hydroquinone dihydroxyethyl ether and 19mL of N, N-dimethylformamide at the temperature of 72 ℃, heating to 85 ℃ and reacting for 35min to obtain a mixture c; mixing the mixture c with 2.5g of 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin, 4g of 2, 4-dihydroxybenzophenone and 22mL of N, N-dimethylformamide at the temperature of 85 ℃ and reacting for 70min at the temperature of 85 ℃ to obtain a mixture d; mixing the mixture d with 0.07g of pentaerythritol tetra (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate), 4g of triethylamine and 13mL of N, N-dimethylformamide at 50 ℃ and carrying out neutralization reaction for 60min to obtain a mixture e; mixing the mixture e with N, N-dimethylformamide to obtain an N, N-dimethylformamide solution of the mixture e with the viscosity of 7500Pa/s, slowly adding 90mL of water with the temperature of 6 ℃ under the condition of stirring rotation speed of 1600r/min, quickly adding the rest 160mL of water after phase inversion is successful, finally adding 0.7mL of diethylenetriamine, and emulsifying for 80min at 26 ℃ to obtain the aqueous polyurethane emulsion.

Example 3

dehydrating 35g of polymer diol (the polymer diol comprises polycaprolactone polyol and polyester diol PBA2000, the mass ratio of the polycaprolactone polyol to the polyester diol PBA2000 is 1:1.7) for 2 hours under the conditions of 10.5kpa of vacuum degree and 75 ℃ of temperature, then cooling to 45 ℃, adding 17g of diisocyanate (the diisocyanate comprises dicyclohexylmethane diisocyanate and isophorone diisocyanate, the mass ratio of dicyclohexylmethane diisocyanate to isophorone diisocyanate is 2.7:1), heating to 65 ℃, and reacting for 70 minutes to obtain a mixture a; mixing the mixture a with 0.25g of dibutyltin dilaurate at the temperature of 65 ℃, then heating to 75 ℃, adding 20mL of N, N-dimethylformamide (the volume of each addition is 5 mL) in 4 times in the heating process, completing mixing, and reacting for 90min at 75 ℃ to obtain a mixture b; mixing the mixture b with 6g of ethylene glycol and 16mL of N, N-dimethylformamide at the temperature of 75 ℃, heating to 82 ℃, and reacting for 38min to obtain a mixture c; mixing the mixture c with 1.5g of 3- (2, 3-dihydroxypropyl) -5, 5-dimethylhydantoin, 3.5g of 2, 4-dihydroxybenzophenone and 17mL of N, N-dimethylformamide at the temperature of 82 ℃ and reacting for 80min at the temperature of 82 ℃ to obtain a mixture d; mixing the mixture d with 0.03g of pentaerythritol tetra (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate), 3.5g of triethylamine and 7mL of N, N-dimethylformamide at a temperature of 52 ℃ and carrying out neutralization reaction for 50min at 52 ℃ to obtain a mixture e; mixing the mixture e with N, N-dimethylformamide to obtain N, N-dimethylformamide solution of the mixture e with the viscosity of 7200Pa/s, slowly adding 95mL of water with the temperature of 4 ℃ under the condition of stirring rotation speed of 1300r/min, quickly adding the rest 200mL of water after phase inversion is successful, finally adding 0.5mL of diethylenetriamine, and emulsifying for 70min at the temperature of 28 ℃ to obtain the aqueous polyurethane emulsion.

The aqueous polyurethane emulsions obtained in examples 2 and 3 were tested for properties by the same test method as in example 1, and the results of comparing the properties of the aqueous polyurethane emulsions obtained in examples 2 and 3 were obtained as shown in Table 2.

Table 2 results of comparison of the Properties of the aqueous polyurethane emulsions obtained in examples 2 and 3

The embodiment of the invention shows that the preparation method of the aqueous polyurethane emulsion is simple in process and controllable in conditions, and the reaction is basically carried out at the medium and low temperature below 100 ℃. The haloamine antibacterial monomer contains an N-H bond, the haloamine antibacterial agent is obtained after hypohalite action, and the molecular structure of the haloamine antibacterial agent contains an N-X bond (wherein X is halogen) and can be repeatedly dehalogenated and halogenated, so that a film formed by coating the aqueous polyurethane emulsion prepared by the invention has good antibacterial reproducibility; in addition, the haloamine antibacterial monomer structure does not contain alpha hydrogen, and the ultraviolet absorber is simultaneously connected into the polyurethane structure, so that the stability of an N-Cl bond is improved, and the film has lasting antibacterial performance; meanwhile, the influence of ultraviolet rays in sunlight on the stability of N-Cl bonds is weakened by introducing the ultraviolet absorber, so that a film formed by coating the aqueous polyurethane emulsion has good antibacterial and light-resistant properties.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. The preparation method of the aqueous polyurethane emulsion is characterized by comprising the following steps of:

。

2. the preparation method of claim 1, wherein the mass ratio of the polymer diol to the diisocyanate in the step (1) is 30-40: 15-20 parts of a base;

3. The preparation method of claim 2, wherein the mass-to-volume ratio of the polymer diol in the step (1) to the dibutyltin dilaurate in the step (2) and the N, N-dimethylformamide is 30-40 g: 0.1-0.3 g: 10-20 mL;

4. The preparation method of claim 3, wherein the mass-to-volume ratio of the polymer diol in the step (1) to the chain extender in the step (3) and the N, N-dimethylformamide is 30-40 g: 5-10 g: 15-20 mL;

5. The method of claim 4, wherein the ultraviolet absorber in step (4) is 2, 4-dihydroxybenzophenone;

6. The process of claim 5, wherein the antioxidant of step (5) is pentaerythritol tetrakis (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate);

7. The method according to claim 6, wherein the mixture e in step (6) has a viscosity of 7000 to 8000pa/s in an N, N-dimethylformamide solution;

and (3) emulsifying at the temperature of 20-30 ℃ for 60-90 min.

8. The aqueous polyurethane emulsion obtained by the preparation method according to any one of claims 1 to 7.

9. The use of the aqueous polyurethane emulsion of claim 8 in synthetic leather products.