Preparation method of one-component waterborne polyurethane coating with hyperbranched structure

Abstract

The application relates to a preparation method of a single-component water-based polyurethane coating with hyperbranched structure. The preparation method of the single-component water-based polyurethane coating with hyperbranched structure comprises the following steps: mixing a small molecule siloxane with a polyhydroxylamine, adding an acid catalyst, performing a reaction, and then performing fractionation and centrifugation to obtain a hydroxyl-terminated hyperbranched organosilicon polymer; mixing diisocyanate and polyglycol, introducing inert gas to perform a reaction, and then obtaining an NCO-terminated water-based polyurethane prepolymer, subsequently adding a catalyst, a hydrophilic chain extender, the hydroxyl-terminated hyperbranched organosilicon polymer and a solvent, performing a reaction, and then obtaining an NCO-terminated hyperbranched water-based polyurethane containing silicon, subsequently adding a fluorine-containing alcohol to perform end capping, performing a reaction, and then cooling; subsequently adding a neutralizing agent to perform neutralization, adding water, performing shear emulsification, and then evaporating and removing the solvent, and then obtaining a fluorine-terminated hyperbranched water-based polyurethane dispersion containing silicon, subsequently adding water, a thickening agent, a leveling agent, a defoaming agent, a wetting dispersant and a bactericidal preservative, and then performing dispersion and stirring to obtain the product.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of one-component modified waterborne polyurethane coatings, and particularly relates to a preparation method of one-component waterborne polyurethane coating with hyperbranched structure. BACKGROUND

[0002] Polyurethane (PU) has been widely used in the fields of coatings, foams, elastomers, leather finishing agents, adhesives, composites, etc. due to its unique properties such as good biocompatibility, microphase separation, and diverse morphological structure. Traditional polyurethane materials use organic solvents as dispersion media. With the improvement of people's environmental awareness and the implementation of sustainable development strategy, countries have successively introduced relevant policies to limit the emission of VOCs, and waterborne polyurethane materials have gradually attracted people's attention. Waterborne polyurethane (WPU) can be divided into single-component WPU and two-component WPU according to different components. Single-component WPU has the characteristics of no need for additional curing agent, ready-to-use, convenient construction, and more environmental protection and no odor compared with two-component WPU. However, neither single-component WPU nor two-component WPU can completely rival solvent-based polyurethane in terms of water resistance and mechanical properties due to the introduction of hydrophilic groups. Therefore, modified WPU has become the research focus of technical personnel.

[0003] Organic fluorine and silicon have large surface tension and strong water repellency. The introduction of fluorine and silicon groups can enhance the water resistance of WPU. More researchers tend to introduce fluorine / silicon groups at the end of linear WPU prepolymer or use organic fluorine / silicon compounds as chain extenders to synthesize linear WPU. However, both of these two methods cannot efficiently exert the water repellency function of fluorine / silicon, and linear WPU still needs to add more organic solvents for dilution due to its high viscosity.

[0004] And hyperbranched polymer has a dense network structure, because of its highly branched structure, the molecular chain is not easy to entangle, the viscosity is low, the adhesion is strong, the leveling property is high and so on, can improve the mechanical properties of WPU, and because the rich end groups of hyperbranched polymer can be modified according to different needs, the introduction of fluorine / silicon group provides more point. At present, the introduction of hyperbranched polymer generally first generates AB2 monomer through Michael addition reaction of double bond ester, and then AB2 monomer is crosslinked with crosslinking agent to synthesize, such as patent CN106349452A relates to preparation of fluorine alkyl terminated hyperbranched polyurethane nano hybrid leather finishing agent, the preparation of hyperbranched nano hybrid polymer of the application utilizes Michael addition reaction of amino modified nano SiO2 and double bond ester, and the time for synthesizing hyperbranched nano hybrid polymer is as long as 10-20h, the reaction time is long, and the Michael addition reaction is a reversible reaction, under heating and alkaline conditions, the product is easy to decompose, resulting in poor controllability of the structure of the prepared hyperbranched nano hybrid polymer, which seriously affects the synthesis of fluorine alkyl terminated hyperbranched polyurethane, the experimental reproducibility is poor, the product synthesis is unstable, and the preparation of fluorine alkyl terminated hyperbranched polyurethane nano hybrid leather finishing agent has organic fluorine alcohol end-capping in front, and hyperbranched nano hybrid polymer is introduced in the back, so the characteristics of the multiple end points of hyperbranched polymer cannot be fully utilized for reaction with fluorine group, therefore, it is particularly important to synthesize a controllable hyperbranched polymer with multiple end points, to fully utilize the hyperbranched structure characteristics, and to avoid the defects of Michael addition reaction. SUMMARY

[0005] The purpose of the present application is to provide a preparation method of one-component waterborne polyurethane coating with hyperbranched structure to solve the technical problems of long preparation process, reversible reaction, poor structure stability of fluorine alkyl terminated hyperbranched polyurethane, and unstable product synthesis.

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

[0007] A preparation method of one-component waterborne polyurethane coating with hyperbranched structure, comprising the following steps: a, synthesis of hydroxyl terminated hyperbranched organosilicon polymer: mixing small molecule siloxane and polyhydroxylamine, adding acid catalyst, reacting at 70-200 DEG C for 1.5-7.5h, and then fractionating and centrifuging, to obtain the product.

[0008] b. Synthesis of -NCO terminated hyperbranched waterborne polyurethane containing silicon: the diisocyanate and polyglycol are mixed and then inert gas is passed through to react, after 1-3 h of reaction at 60-100°C, the NCO terminated waterborne polyurethane prepolymer is obtained, then the temperature is lowered, the catalyst, hydrophilic chain extender, the hydroxyl terminated hyperbranched silicone polymer in step a and solvent are added, after 1-3.5 h of reaction at 65-105°C, the temperature is lowered, then the neutralizer is added to neutralize, then water is added to shear emulsify at 1500-3500 r / min, and the solvent is evaporated to obtain the product;

[0009] c. Synthesis of fluorine terminated hyperbranched waterborne polyurethane containing silicon dispersion: the -NCO terminated hyperbranched waterborne polyurethane containing silicon in step b is capped with fluorine-containing alcohol, after 1-3.5 h of reaction at 65-105°C, the temperature is lowered, then the neutralizer is added to neutralize, then water is added to shear emulsify at 1500-3500 r / min, and the solvent is evaporated to obtain the product;

[0010] d. The fluorine terminated hyperbranched waterborne polyurethane containing silicon dispersion obtained in step c is added with water, thickening agent, leveling agent, defoaming agent, wetting dispersant, bactericidal preservative, and dispersed and stirred at 50-500 r / min for 0.5-2.5 h to obtain the product.

[0011] Further, the temperature of the temperature lowering in step b is 40-65°C, and the temperature of the temperature lowering in step c is 25-40°C.

[0012] Further, the molar ratio of the small molecule siloxane to the polyhydroxylamine in step a is 1-31:2-63, and the acid catalyst accounts for 0.05-0.5% of the total weight of the small molecule siloxane and polyhydroxylamine.

[0013] Further, the molar ratio of the diisocyanate to the polyglycol in step b is 1.5-5:1, the catalyst accounts for 0.0075-0.075% of the total weight of the diisocyanate and polyglycol, and the hydrophilic chain extender accounts for 2.0-7.0% of the total weight of the diisocyanate and polyglycol.

[0014] Further, the neutralizer in step c is 80-120% of the molar mass of the acidic group in the -NCO terminated hyperbranched waterborne polyurethane containing silicon.

[0015] Further, the end-fluorine-containing silicon-containing hyperbranched aqueous polyurethane dispersion in step d accounts for 65-85% of the total weight of the single-component hyperbranched aqueous polyurethane coating; the thickening agent accounts for 0.1-3.0% of the total weight of the single-component hyperbranched aqueous polyurethane coating; the leveling agent accounts for 0.03-0.50% of the total weight of the single-component hyperbranched aqueous polyurethane coating; the defoaming agent accounts for 0.03-0.40% of the total weight of the single-component hyperbranched aqueous polyurethane coating; the wetting dispersant accounts for 0.4-2.0% of the total weight of the single-component hyperbranched aqueous polyurethane coating; and the bacteriostatic preservative accounts for 0.05-0.10% of the total weight of the single-component hyperbranched aqueous polyurethane coating.

[0016] Further, the small molecule siloxane in step a is one or more of triethoxymethylsilane, ethyl triethoxysilane, dimethyldiethoxysilane, phenyl triethoxysilane, diphenyl diethoxysilane, benzyl triethoxysilane, and monofluoro triethoxysilane;

[0017] The polyhydroxylamine is one or more of 2,2'-dihydroxydiethylamine, 2,2',2''-hydroxytriethylamine, 2,2'-dihydroxydipropylamine, tris(2-hydroxypropyl)amine, N,N-bis(β-hydroxyethyl)methylamine, and 1,1'-(methylimino)bis(2-propanol); and the acid catalyst is supported phosphotungstic acid.

[0018] Further, the diisocyanate in step b is one or more of isophorone diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, lysine diisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene, and toluene diisocyanate;

[0019] The polyhydric alcohol is one or more of polycarbonate diol, polyethylene adipate diol, polybutylene adipate diol, poly-ε-caprolactone diol, polyadipate castor oil dihydric alcohol, polytetrahydrofuran dihydric alcohol, polyethylene glycol, polypropylene glycol, and polybutadiene dihydric alcohol;

[0020] The polyhydric alcohol has a molecular weight of 500-5000;

[0021] The inert gas is one or more of dry nitrogen, argon, helium, and neon;

[0022] The catalyst is one or more of dibutyltin dilaurate, stannous octoate, zinc octoate, bismuth neodecanoate, triethylenediamine, dibutyltin maleate, and dibutyltin diacetate;

[0023] The hydrophilic chain extender is one or more of 2,2-dimethylol propionic acid, 2,2-dimethylol butyric acid, tartaric acid, N,N-dihydroxy monomaleamic acid, 1,2-dihydroxy-3-propanesulfonic acid sodium, 1,4-butanediol-2-sulfonic acid sodium;

[0024] The solvent is acetone; the polyhydric alcohol and the hydrophilic chain extender need to be vacuum dehydrated at a temperature of 50-120℃ and a vacuum degree of -0.09 to -0.10 MPa for 1-3h.

[0025] Further, in step c, the fluorine-containing alcohol is one or more of perfluoroalkyl ethanol, 2,2,3,3-tetrafluoropropanol, 2-perfluoropropoxy-2,3,3,3-tetrafluoropropanol, 2,2,3,4,4,4-hexafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 1H,1H,2H,2H-perfluorooctanol, 1H,1H-perfluoro-3,5,5-trimethyl-1-hexanol, and hexafluoropropylene oxide dimer alcohol;

[0026] The neutralizing agent is one or more of sodium hydroxide, triethylamine, and N,N dimethyl ethanolamine.

[0027] Further, in step d, the thickening agent is one or more of Acrysol RM-8W, Acrysol RM-12W, and ADEKANOL UH series products;

[0028] The leveling agent is one or more of TEGO Glide 100, TEGO Glide 410, TEGO flow 425, TEGO Glide 450, TEGO Glide 496, and TEGO Glide ZG 400;

[0029] The defoaming agent is one or more of silicone defoaming agents ACP-1400, ACP-0544, AFE-1430, AFE-0500, AFE-0800, KS66, and UNIQFOAM 290W;

[0030] The wet dispersing agent is one or more of aqueous wet dispersing agents DISPERBYK-180, DISPERBYK-182, DISPERBYK-190, DISPERBYK-2010, DISPERBYK-2012, and DISPERBYK-2055;

[0031] The bactericidal preservative is one or more of Clariant Nipacide BNPD 20, Clariant Nipacide HF-I, Clariant Nipacide CI 15MV, and Clariant Nipacide IPBC 10.

[0032] Advantages of the present application:

[0033] The prepared end-fluorine-containing silicon hyperbranched waterborne polyurethane dispersion has a hyperbranched structure, and the highly branched three-dimensional network structure endows it with excellent mechanical properties.

[0034] The one-component waterborne polyurethane coating with a hyperbranched structure according to the present application is used in waterborne automobile coatings, uses water as a dispersion medium, is environmentally friendly, odorless, non-toxic and non-flammable, actively and effectively improves the current situation of low hardness and insufficient water resistance of one-component waterborne polyurethane, and is easy to paint, greatly reduces the construction cost, and because the end-fluorine-containing silicon hyperbranched waterborne polyurethane dispersion has a rich cavity structure, it can better fill other fillers.

[0035] The one-component waterborne polyurethane coating with a hyperbranched structure according to the present application has the characteristics of high hardness, strong water resistance, good heat and temperature storage performance, strong adhesion, accurate synthesis route, and high group utilization rate, and the water resistance can be obviously improved by introducing a small amount of fluorine and silicon groups, and has high application value in the fields of high-hardness, waterproof coatings, automobile coatings and the like. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The infrared spectrum of the raw material phenyltriethoxysilane, 2,2',2"-hydroxytriethylamine and the product HBPSi-OH in Example 1 is shown in Figure 1. II-24 The infrared spectrum of the raw material phenyltriethoxysilane, 2,2',2"-hydroxytriethylamine and the product HBPSi-OH in Example 1 is shown in Figure 1.

[0037] Figure 2 The infrared spectrum of the raw material phenyltriethoxysilane, 2,2',2"-hydroxytriethylamine and the product HBPSi-OH in Example 1 is shown in Figure 1.

[0038] Figure 3 The infrared spectrum of the raw material phenyltriethoxysilane, 2,2',2"-hydroxytriethylamine and the product HBPSi-OH in Example 1 is shown in Figure 1. Detailed Implementation

[0039] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0040] A first-generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH) is obtained by mixing small molecule siloxanes and polyhydroxyamines in a molar ratio of 1:2-3. I A second-generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH) is obtained by using a small molecule siloxane to polyhydroxyamine molar ratio of 4–7:6–15. II A third-generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH) is obtained by using a molar ratio of small molecule siloxane to polyhydroxyamine of 10–31:14–63. III );

[0041] The first-generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OHI) can be one or more of the following: a trifunctional small molecule siloxane to a trifunctional polyhydroxylamine molar ratio of 1:3, a trifunctional small molecule siloxane to a difunctional polyhydroxylamine molar ratio of 1:3, or a difunctional small molecule siloxane to a trifunctional polyhydroxylamine molar ratio of 1:2. The designation HBPSi-OH is based on the number of -OH groups present. I-6 HBPSi-OH I-3 HBPSi-OH I-4 ;

[0042] Second-generation hydroxyl-terminated hyperbranched organosilicon polymers (HBPSi-OH) II The substance can be one or more of the following: a trifunctional small molecule siloxane to a trifunctional polyhydroxylamine molar ratio of 7:15, a trifunctional small molecule siloxane to a difunctional polyhydroxylamine molar ratio of 4:9, or a difunctional small molecule siloxane to a trifunctional polyhydroxylamine molar ratio of 5:6. The substance is represented as HBPSi-OH based on the number of -OH groups it carries. II-24 HBPSi-OH II-6 HBPSi-OH II-8 ;

[0043] Third-generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH) III It can be one or more of the following: a trifunctional small molecule siloxane to a trifunctional polyhydroxylamine molar ratio of 31:63, a trifunctional small molecule siloxane to a difunctional polyhydroxylamine molar ratio of 10:21, or a difunctional small molecule siloxane to a trifunctional polyhydroxylamine molar ratio of 13:14, and is represented as HBPSi-OH according to the number of -OH groups. III-102 HBPSi-OH III-12 HBPSi-OH III-20 .

[0044] Immobilized phosphotungstic acid is supported on MCM-41 molecular sieve, 40% loading.

[0045] Example 1

[0046] The preparation method of the single-component waterborne polyurethane coating with hyperbranched structure of the present example comprises the following steps:

[0047] a. Synthesis of hydroxyl-terminated hyperbranched silicone polymer: 0.34 g of phenyltriethoxysilane, 0.64 g of 2,2',2"-hydroxytriethylamine, and 0.03 g of immobilized phosphotungstic acid are added to a container with mechanical stirring, nitrogen atmosphere, and a condenser. After 2 h of reaction at 100°C without distillate, 2 g of phenyltriethoxysilane and 2.5 g of 2,2',2"-hydroxytriethylamine are added, and the reaction is continued for 2 h without distillate. The immobilized phosphotungstic acid is removed by centrifugation, and the byproduct is removed by vacuum at 70°C for 0.5 h to obtain a second-generation hydroxyl-terminated hyperbranched silicone polymer (HBPSi-OH II-24 ), and the reaction process is shown in Formula I:

[0048]

[0049] b. 33.5 g of polycarbonate diol (PCDL-1500) is placed in a container, vacuumed at -0.095 MPa and 120°C for 2 h, and then a nitrogen tube, a reflux condenser, and a mechanical stirring device are configured on the container. 11 g of isophorone diisocyanate is added dropwise to the container, and the reaction is carried out at 85°C for 2 h. The reaction endpoint is determined by the di-n-butylamine method, and when the NCO content reaches the theoretical value, a -NCO terminated waterborne polyurethane prepolymer (PPU) is synthesized, and the reaction formula is shown in Formula II:

[0050]

[0051] Then the reaction system is cooled to 60°C, and 0.0038 g of dibutyltin diacetate, 2 g of 2,2-dimethylol propionic acid dissolved in 2 g of N-methyl pyrrolidone, 0.3 g of HBPSi-OH II-24 , and 15 g of acetone are added, and the temperature is controlled at 75°C for 2 h. The reaction endpoint is determined by the di-n-butylamine method, and when the NCO content reaches the theoretical value, a -NCO terminated hyperbranched silicone-containing waterborne polyurethane (HBPSiPU) is obtained, and the reaction formula is shown in Formula III; 2,2-dimethylol propionic acid needs to be vacuumed at -0.095 MPa and 120°C for 2 h.

[0052]

[0053] c. On the basis of the synthesis of HBPSiPU in step b, 4.2 g of 2,2,3,4,4,4-hexafluoro-1-butanol was added to the container for capping, and the temperature was controlled at 75 ℃ for 1 h, and the reaction end point was determined by the di-n-butylamine method. When the NCO content reached the theoretical value, the reaction system was cooled to 40 ℃, 1.4 g of triethylamine was added and neutralized for 0.5 h, then 78 g of deionized water was added, and the emulsion was obtained by high-speed shearing for 0.5 h at 2500 r / min, and then the acetone was removed by rotary evaporation to obtain a fluorine-terminated silicon-containing hyperbranched waterborne polyurethane dispersion (HBPSiPUF).

[0054] d. The HBPSiPUF prepared in c was sequentially added with 0.23 g of Acrysol RM-8W, 0.13 g of TEGO Glide100, 0.39 g of ACP-1400, 0.52 g of DISPERBYK-180, 0.07 g of Clariant Nipacide BNPD 20, and 26 g of deionized water, and was dispersed and stirred at 200 r / min for 0.5 h, and then was filtered to obtain a one-component waterborne polyurethane coating material with a hyperbranched structure.

[0055] Figure 1 The infrared spectra of the raw materials phenyltriethoxysilane, 2,2',2"-hydroxytriethylamine, and the product HBPSi-OH are shown in curves (a), (b), and (c), respectively. II-24 -1 -1 Both 3372 cm -1 and 3441 cm -1 are -OH stretching vibration peaks, and it can be seen that the -OH stretching vibration peak in (c) is red-shifted and the peak shape is broadened, indicating that a large amount of -OH is associated. 1090 cm -1 is a -Si-O-C- characteristic peak, and 744 cm II-24 and 694 cm -1 are -C-H out-of-plane bending vibration peaks of a monosubstituted benzene ring, indicating the synthesis of hydroxyl-capped HBPSi-OH.

[0056] Figure 2 The infrared spectra of anhydrous ethanol and the distillate are shown in curves (a) and (b), respectively. 3359 cm -1 in (b) is an -OH stretching vibration peak, 2977 cm -1 and 2888 cm -1 are -CH3 and -CH2 stretching vibration peaks, 1454 cm -1 and 1382 cm -1 are -CH3 and -CH2 bending vibration peaks, 1089 cm -1 and 1050 cm -1 ​​The infrared spectrum of the distillate was highly consistent with that of anhydrous ethanol, and was in accordance with the expectation of the reaction.

[0057] Figure 3 Curves (a), (b) and (c) are infrared spectra of raw material isophorone diisocyanate, 2,2,3,4,4,4-hexafluoro-1-butanol and product HBPSiPUF respectively, wherein the 2260 cm -1 in (a) is an absorption peak of -NCO, the 3367 cm -1 in (c) is a stretching vibration peak of -NH in -NHCOO in the synthesis, the 1230 cm -1 is a stretching vibration peak of -C-O-C in -NHCOO, the 1727 cm -1 is a vibration absorption peak of -C=O, the 1532 cm -1 is a stretching vibration of -C-N and in-plane bending vibration of -NH, the 1360 cm -1 , 1164 cm -1 , 838 cm -1 is a characteristic peak of -CF, -CF2 and -CF3, the 1110 cm -1 is a characteristic peak of -Si-O-C-, and the 2270-2250 cm -1 is no -NCO absorption peak, indicating that the -NCO group is completely reacted and F and Si elements are introduced into the polyurethane molecular chain, and the HBPSiPUF is successfully synthesized.

[0058] Example 2

[0059] a, 0.89 g of triethoxymethylsilane, 1.79 g of N,N-bis(β-hydroxyethyl)methylamine and 0.04 g of immobilized phosphotungstic acid were added to a container with mechanical stirring, nitrogen atmosphere and a condenser tube, and reacted at 90°C for 2 h until no distillate was distilled out, then 2.67 g of methyltriethoxysilane and 3.57 g of N,N-bis(β-hydroxyethyl)methylamine were added, and the reaction was continued for 2 h until no distillate was distilled out, then the immobilized phosphotungstic acid was removed by centrifugation, and the by-product was removed by vacuumizing at 70°C for 0.5 h, to obtain a second generation of hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH II-6 ) for standby use.

[0060] b、First, 57 g of poly-ε-caprolactone diol (PCL-2000) was placed in a container, vacuumed at -0.095 MPa and 120°C for 2 h, and then a nitrogen tube, a reflux condenser, and a mechanical stirring device were arranged on the container. 12 g of toluene diisocyanate was added dropwise into the container, and reacted at 90°C for about 2 h. The reaction end point was determined by the di-n-butylamine method. When the NCO content reached the theoretical value, the -NCO capped waterborne polyurethane prepolymer was synthesized. Then, the reaction system was cooled to 60°C, 0.005 g of dibutyltin maleate, 3.2 g of 2,2-dimethylol butyric acid, 0.6 g of HBPSi-OH II-6 , and 24 g of acetone were added, and the temperature was controlled at 80°C for 2 h. After the reaction end point was determined by the di-n-butylamine method, when the NCO content reached the theoretical value, the second generation -NCO capped hyperbranched silicon-containing waterborne polyurethane was obtained. The 2,2-dimethylol butyric acid needs to be vacuumed at -0.095 MPa and 120°C for 2 h.

[0061] c、On the basis of the synthesis of HBPSiPU in step b, 4.8 g of 2,2,3,3-tetrafluoropropyl alcohol was added to the container for capping, and the temperature was controlled at 85°C for 1 h. The reaction end point was determined by the di-n-butylamine method. After the NCO content reached the theoretical value, the reaction system was cooled, and 0.83 g of sodium hydroxide was added to neutralize for 0.5 h when the reaction system was cooled to 40°C. Then, 122 g of deionized water was added, and the mixture was emulsified at a high speed of 2750 r / min for 0.5 h. After the acetone was removed by rotary evaporation, the fluorine-terminated silicon-containing hyperbranched waterborne polyurethane dispersion was obtained.

[0062] d、The HBPSiPUF prepared in c was sequentially added with 0.3 g of Acrysol RM-12W, 0.16 g of TEGO Glide410, 0.5 g of ACP-0544, 0.91 g of DISPERBYK-182, 0.1 g of Clariant Nipacide HF-I, and 42 g of deionized water, and dispersed and stirred at 300 r / min for 0.5 h. After filtration, the one-component waterborne polyurethane coating with a hyperbranched structure was obtained.

[0063] Example 3:

[0064] a、0.44 g of dimethyldiethoxysilane, 1.15 g of tris(2-hydroxypropyl)amine, and 0.023 g of immobilized phosphotungstic acid were added to a container with mechanical stirring, a nitrogen atmosphere, and a condenser. After no distillate was distilled out at 100°C for 2 h, 1.78 g of dimethyldiethoxysilane and 2.3 g of tris(2-hydroxypropyl)amine were added, and the reaction was continued for 2 h until no distillate was distilled out. The immobilized phosphotungstic acid was removed by centrifugation, and the byproduct was removed by vacuuming at 70°C for 0.5 h. Thus, the second generation hydroxyl-terminated hyperbranched silicone polymer (HBPSi-OH II-8 ) was obtained and ready for use.

[0065] b、First, 27.5 g of polycarbonate diol (PCDL-1000) is placed in a container, vacuumed at -0.095 MPa, 120°C for 2 h, and then a nitrogen tube, a reflux condenser, and a mechanical stirring device are configured on the container. 10 g of hexamethylene diisocyanate is added dropwise to the container, and reacted at 95°C for about 2 h, with the reaction endpoint determined by the di-n-butylamine method. When the NCO content reaches the theoretical value, a -NCO capped waterborne polyurethane prepolymer is synthesized. Then, the reaction system is cooled to 60°C, and 0.0034 g of bismuth neodecanoate, 2 g of 1.88 g of 2,2-dimethylol propionic acid dissolved in N,N-dimethylformamide, 0.5 g of HBPSi-OH II-8 and 13 g of acetone are added, and the temperature is controlled at 75°C for 2 h of reaction. The reaction endpoint is determined by the di-n-butylamine method. When the NCO content reaches the theoretical value, a second generation -NCO capped hyperbranched silicon-containing waterborne polyurethane is obtained. The 2,2-dimethylol propionic acid needs to be vacuumed at -0.095 MPa, 120°C for 2 h.

[0066] c、On the basis of the synthesis of HBPSiPU in step b, 6.24 g of 2,2,3,4,4,4-hexafluoro-1-butanol is added to the container for capping, and the temperature is controlled at 75°C for 1 h of reaction. The reaction endpoint is determined by the di-n-butylamine method. After the NCO content reaches the theoretical value, the reaction system is cooled, and when it is cooled to 40°C, 1.25 g of N,N-dimethyl ethanolamine is added for neutralization for 0.5 h. Then, 74 g of deionized water is added, and emulsified at a high speed of 2000 r / min for 0.5 h. The acetone is removed by rotary evaporation to obtain a fluorine-terminated silicon-containing hyperbranched waterborne polyurethane dispersion.

[0067] d、0.2 g of ADEKANOL UH-420, 0.16 g of TEGOflow 425, 0.34 g of AFE-1430, 0.61 g of DISPERBYK-190, 0.06 g of Clariant Nipacide CI 15MV, 27 g of deionized water are sequentially added to the HBPSiPUF prepared above, and dispersed and stirred at 250 r / min for 0.5 h. Filtration obtains a single-component waterborne polyurethane coating with hyperbranched structure, high hardness, and high water resistance.

[0068] Example 4:

[0069] a. Put 0.06 g monofluorotriethoxysilane, 0.14 g 2,2',2"-hydroxytriethylamine and 0.017 g immobilized phosphotungstic acid into a container with mechanical stirring, nitrogen atmosphere and condenser, react at 110 ℃ for 1.5 h until no distillate is distilled out, then add 0.35 g monofluorotriethoxysilane and 0.58 g 2,2',2"-hydroxytriethylamine, continue to react for 1.5 h until no distillate is distilled out, then add 1.4 g monofluorotriethoxysilane and 2.3 g 2,2',2"-hydroxytriethylamine, continue to react for 1.5 h until no distillate is distilled out, centrifuge to remove the immobilized phosphotungstic acid, vacuum at 70 ℃ for 0.5 h to remove byproducts, and the third generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH III-102 ) is obtained.

[0070] b. First, put 30.8 g polybutylene adipate glycol (PBA-2000) into a container, vacuum at -0.095 MPa and 120 ℃ for 2 h, then configure a nitrogen tube, a reflux condenser and a mechanical stirring device on the container, add 10.5 g dicyclohexyl methane diisocyanate dropwise into the container, react at 85 ℃ for 2 h, and determine the reaction endpoint by the di-n-butylamine method; when the NCO content reaches the theoretical value, the -NCO terminated waterborne polyurethane prepolymer is synthesized; then cool the reaction system to 60 ℃, add 0.004 g dibutyltin dilaurate, 2 g 1,2-dihydroxy-3-propanesulfonic acid sodium dissolved in N-methylpyrrolidone, 0.25 g HBPSi-OH III-102 and 14.5 g acetone, control the temperature at 80 ℃ for 2 h, and determine the reaction endpoint by the di-n-butylamine method; when the NCO content reaches the theoretical value, the third generation -NCO terminated hyperbranched silicon-containing waterborne polyurethane is obtained; the 1,2-dihydroxy-3-propanesulfonic acid sodium needs to be vacuumed at -0.095 MPa and 120 ℃ for 2 h.

[0071] c. On the basis of the synthesis of HBPSiPU in step b, add 5.8 g 2,2,3,3,4,4,5,5-octafluoro-1-pentanol to the container for capping, control the temperature at 80 ℃ for 1 h, determine the reaction endpoint by the di-n-butylamine method, cool down when the NCO content reaches the theoretical value, add 1.17 g triethylamine to neutralize for 0.5 h when the reaction system is cooled to 40 ℃, then add 79 g deionized water, high-speed shear emulsify at 2500 r / min for 0.5 h, and rotary evaporate to remove acetone, and the fluorine-terminated silicon-containing hyperbranched waterborne polyurethane dispersion is obtained.

[0072] d. In the above prepared HBPSiPUF, 0.21 g of ADEKA NO LUH-541, 0.16 g of TEGO Glide 450, 0.35 g of AFE-0500, 0.65 g of DISPERBYK-2010, 0.06 g of Clariant Nipacide IPBC10, and 29.8 g of deionized water were sequentially added, and dispersed and stirred at 250 r / min for 0.5 h, and then filtered to obtain a hyperbranched structure high hardness high water resistance one-component waterborne polyurethane coating.

[0073] Example 5:

[0074] a. 0.19 g of benzyl triethoxysilane, 0.33 g of 1,1'-(methylimino) bis(2-propanol), and 0.019 g of immobilized phosphotungstic acid were added to a container with mechanical stirring, a nitrogen atmosphere, and a condenser, and reacted at 120°C for 1.5 h until no distillate was distilled out. Then, 0.57 g of benzyl triethoxysilane and 0.66 g of 1,1'-(methylimino) bis(2-propanol) were added, and the reaction was continued for 1.5 h until no distillate was distilled out. Then, 1.14 g of benzyl triethoxysilane and 1.32 g of 1,1'-(methylimino) bis(2-propanol) were added, and the reaction was continued for 1.5 h until no distillate was distilled out. The immobilized phosphotungstic acid was removed by centrifugation, and the byproducts were removed by vacuum extraction at 70°C for 0.5 h to obtain a third generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH III-12 ), which was ready for use.

[0075] b. First, 12.45 g of poly-ε-caprolactone diol (PCL-1000) was placed in a container, and vacuum extraction was performed at -0.095 MPa and 120°C for 2 h. Then, a nitrogen tube, a reflux condenser, and a mechanical stirring device were arranged on the container, 7.5 g of diphenylmethane-4,4'-diisocyanate was added dropwise to the container, and the reaction was performed at 75°C for about 2 h, and the reaction endpoint was determined by the di-n-butylamine method. When the NCO content reached the theoretical value, a -NCO terminated waterborne polyurethane prepolymer was synthesized. Then, the reaction system was cooled to 60°C, 0.0015 g of stannous octoate, 1 g of N-methylpyrrolidone dissolved 0.94 g of 1,2-dihydroxy-3-propanesulfonic acid sodium, 0.35 g of HBPSi-OH III-12, and 7 g of acetone were added, and the reaction was performed at 75°C for 2 h, and the reaction endpoint was determined by the di-n-butylamine method. When the NCO content reached the theoretical value, a second generation -NCO terminated hyperbranched silicon-containing waterborne polyurethane was obtained. The 1,2-dihydroxy-3-propanesulfonic acid sodium needs to be vacuum extracted at -0.095 MPa and 120°C for 2 h.

[0076] c. Based on the synthesis of HBPSiPU in step b, 2.61g of perfluoroalkyl ethanol was added to the container for end-capping. The temperature was controlled at 75℃ for 1h. The reaction endpoint was determined by the di-n-butylamine method. When the NCO content reached the theoretical value, the temperature was lowered. When the reaction system was cooled to 40℃, 0.56g of triethylamine was added for neutralization for 0.5h. Then, 39g of deionized water was added, and the mixture was emulsified by high-speed shearing at 2000r / min for 0.5h. Acetone was then removed by rotary evaporation to obtain the fluorinated, silicon-containing hyperbranched waterborne polyurethane dispersion.

[0077] d. Add 0.11g of ADEKANOLUH-752, 0.1g of TEGOGlide 496, 0.2g of AFE-0800, 0.29g of DISPERBYK-2012, 0.03g of Clariant Nipacide HF-I, and 15g of deionized water to the HBPSiPUF prepared above. Disperse and stir at 225r / min for 0.5h, and filter to obtain a high-hardness, high-water-resistant single-component waterborne polyurethane coating with hyperbranched structure.

[0078] Example 6:

[0079] a) 0.21 g of diphenyldiethoxysilane, 0.29 g of tris(2-hydroxypropyl)amine, and 0.024 g of supported phosphotungstic acid were added to a container equipped with mechanical stirring, a nitrogen atmosphere, and a condenser. The mixture was reacted at 135 °C for 1.5 h until no distillate was obtained. Then, 0.84 g of diphenyldiethoxysilane and 0.59 g of tris(2-hydroxypropyl)amine were added, and the reaction was continued for another 1.5 h until no distillate was obtained. Next, 1.68 g of diphenyldiethoxysilane and 1.18 g of tris(2-hydroxypropyl)amine were added, and the reaction was continued for another 1.5 h until no distillate was obtained. The supported phosphotungstic acid was removed by centrifugation, and the mixture was vacuumed at 70 °C for 0.5 h to remove byproducts, thus obtaining the third-generation hydroxyl-terminated hyperbranched organosilicon polymer (HBPSi-OH). III-20 ),spare.

[0080] b. First, 28.4g of polybutylene adipate diol (PBA-1500) was placed in a container and evacuated for 2 hours at -0.095MPa and 120℃. Then, a nitrogen tube, a reflux condenser, and a mechanical stirrer were installed on the container. 8.9g of isophorone diisocyanate was added dropwise to the container, and the reaction was carried out at 75℃ for about 2 hours. The reaction endpoint was determined using the di-n-butylamine method. When the NCO content reached the theoretical value, the -NCO-terminated waterborne polyurethane prepolymer was synthesized. Afterward, the temperature was lowered to 60℃, and 0.0024g of a mixture of dibutyltin dilaurate and stannous octoate, 2g of 1.87g of sodium 1,4-butanediol-2-sulfonate dissolved in N,N-dimethylformamide, and 0.3g of HBPSi-OH were added. III-20and 13 g of acetone, and the reaction was carried out at 75°C for 2 h. The reaction was terminated by the dibutylamine method. When the NCO content reached the theoretical value, the third generation NCO-terminated hyperbranched waterborne polyurethane containing silicon was obtained. The 1,4-butanediol-2-sodium sulfonate was vacuumed at -0.095 MPa and 120°C for 2 h.

[0081] c. On the basis of step b, 7.2 g of hexafluoropropylene oxide dimer alcohol was added to the container to terminate the reaction, and the reaction was carried out at 75°C for 1 h. The reaction was terminated by the dibutylamine method. When the NCO content reached the theoretical value, the temperature was lowered. When the reaction system was cooled to 40°C, 0.73 g of N,N-dimethylethanolamine was added and neutralized for 0.5 h. Then, 71 g of deionized water was added, and the mixture was emulsified at 3500 r / min for 0.5 h. Acetone was removed by rotary evaporation to obtain a fluorine-terminated hyperbranched waterborne polyurethane containing silicon dispersion.

[0082] d. In the HBPSiPUF prepared above, 0.19 g of Acrysol RM-8W, 0.07 g of TEGO Glide ZG 400, 0.32 g of UNIQFOAM 290W, 0.48 g of DISPERBYK-2055, 0.06 g of Clariant Nipacide CI 15MV, and 30 g of deionized water were sequentially added. The mixture was dispersed and stirred at 275 r / min for 0.5 h, and then filtered to obtain a hyperbranched structure high-hardness high-water-resistance one-component waterborne polyurethane coating.

[0083] Comparative Example 1

[0084] The preparation method of the waterborne polyurethane coating of Comparative Example 1 was substantially the same as that of Example 1. The difference between the preparation method of the waterborne polyurethane coating of Comparative Example 1 and that of Example 1 was that step a in Example 1 was removed in Comparative Example 1.

[0085] Comparative Example 2

[0086] The preparation method of the waterborne polyurethane coating of Comparative Example 2 was substantially the same as that of Example 1. The difference between the preparation method of the waterborne polyurethane coating of Comparative Example 2 and that of Example 1 was that step c in Example 1 was removed in Comparative Example 2.

[0087] The varnish film performance of Example 1-6 and Comparative Example 1-2 and the comparative performance of HG / T 4761-2014 waterborne polyurethane coating are shown in Table 1 below.

[0088] Table 1 Comparative performance of varnish film performance of Example 1-6 and Comparative Example 1-2 and HG / T 4761-2014 waterborne polyurethane coating

[0089]

[0090]

[0091] It can be found from Table 1 that the single-component waterborne polyurethane coating with hyperbranched structure of the application meets the industry standard only in varnish (without high-hardness filler), and far exceeds the standard requirements in heat storage, hardness, water resistance and the like, and the hardness, water resistance and water contact angle of the varnish of Comparative Examples 1 and 2 are lower than those of each example without adding hyperbranched polymer and without fluorine capping, which effectively proves the excellent effect of the synthetic route in the patent on the performance. It has good application prospect in high-hardness, waterproof coating and automobile coating.

Claims

1. A method for preparing a one-component waterborne polyurethane coating having a hyperbranched structure, characterized in that, The method comprises the following steps: Synthesis of the hydroxyl-terminated hyperbranched organosilicon polymer: mix small molecule siloxane with polyhydroxylamine, add acid catalyst, and react at 70-200 ℃ for 1.5-7.5 h, then fractionate and centrifuge to obtain the product; Synthesis of the NCO-terminated hyperbranched waterborne polyurethane containing silicon: mix diisocyanate and polyglycol, and then introduce inert gas to react at 60-100 ℃ for 1-3 h to obtain the NCO-terminated waterborne polyurethane prepolymer, then cool down, add catalyst, hydrophilic chain extender, the hydroxyl-terminated hyperbranched organosilicon polymer in step a, and solvent, and react at 65-105 ℃ for 1-3.5 h to obtain the product; Synthesis of the fluorine-terminated hyperbranched waterborne polyurethane containing silicon: add fluorine-containing alcohol to the NCO-terminated hyperbranched waterborne polyurethane containing silicon in step b to terminate, react at 65-105 ℃ for 1-3.5 h, cool down, then add neutralizer to neutralize, add water to shear emulsify, and evaporate the solvent to obtain the product; Add water, thickening agent, leveling agent, defoaming agent, wetting dispersant, and bacteriostatic preservative to the fluorine-terminated hyperbranched waterborne polyurethane containing silicon obtained in step c, and disperse and stir at 50-500 r / min for 0.5-2.5 h to obtain the product.

2. The method for preparing a monocomponent waterborne polyurethane coating having a hyperbranched structure according to claim 1, characterized in that, The cooling temperature in step b is 40-65 ℃, and the cooling temperature in step c is 25-40 ℃.

3. The method for preparing a monocomponent waterborne polyurethane coating having a hyperbranched structure according to claim 1, characterized in that, The molar ratio of the small molecule siloxane to the polyhydroxylamine in step a is 1-31:2-63, and the acid catalyst accounts for 0.05-0.5 % of the total weight of the small molecule siloxane and polyhydroxylamine.

4. The method for preparing a monocomponent waterborne polyurethane coating having a hyperbranched structure according to claim 1, characterized in that, The molar ratio of the diisocyanate to the polyglycol in step b is 1.5-5:1, the catalyst accounts for 0.0075-0.075 % of the total weight of the diisocyanate and polyglycol, and the hydrophilic chain extender accounts for 2.0-7.0 % of the total weight of the diisocyanate and polyglycol.

5. The method of claim 1, wherein the method is characterized by, The neutralizer in step c accounts for 80-120 % of the molar number of the acidic groups in the NCO-terminated hyperbranched waterborne polyurethane containing silicon.

6. The method for preparing a monocomponent waterborne polyurethane coating having a hyperbranched structure according to claim 1, characterized in that, In step d, the fluorine-terminated hyperbranched waterborne polyurethane containing silicon accounts for 65-85 % of the total weight of the single-component waterborne polyurethane coating with hyperbranched structure, the thickening agent accounts for 0.1-3.0 % of the total weight of the single-component waterborne polyurethane coating with hyperbranched structure, the leveling agent accounts for 0.03-0.50 % of the total weight of the single-component waterborne polyurethane coating with hyperbranched structure, the defoaming agent accounts for 0.03-0.40 % of the total weight of the single-component waterborne polyurethane coating with hyperbranched structure, the wetting dispersant accounts for 0.4-2.0 % of the total weight of the single-component waterborne polyurethane coating with hyperbranched structure, and the bacteriostatic preservative accounts for 0.05-0.10 % of the total weight of the single-component waterborne polyurethane coating with hyperbranched structure.

7. The method of claim 1, wherein the method is characterized by, The small molecule siloxane in step a is one or more of triethoxymethylsilane, ethyl triethoxysilane, dimethyldiethoxysilane, phenyl triethoxysilane, diphenyldiethoxysilane, benzyl triethoxysilane, monofluoro triethoxysilane; The polyhydroxylamine is one or more of 2,2'-dihydroxydiethylamine, 2,2',2''-hydroxytriethylamine, 2,2'-dihydroxydipropylamine, tris(2-hydroxypropyl)amine, N,N-bis(β-hydroxyethyl)methylamine, 1,1'-(methylimino)bis(2-propanol); the acid catalyst is supported phosphotungstic acid.

8. The method for preparing a monocomponent waterborne polyurethane coating having a hyperbranched structure according to claim 1, characterized in that, The diisocyanate in step b is one or more of isophorone diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, lysine diisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene, toluene diisocyanate; The polyhydric alcohol is one or more of polycarbonate diol, polyethylene glycol adipate diol, polybutylene glycol adipate diol, poly-ε-caprolactone diol, polyricinoleic acid adipate dihydric alcohol, polytetrahydrofuran dihydric alcohol, polyethylene glycol, polypropylene glycol, polybutadiene dihydric alcohol; The polyhydric alcohol has a molecular weight of 500-5000; The inert gas is one or more of dry nitrogen, argon, helium, neon; The catalyst is one or more of dibutyltin dilaurate, stannous octoate, zinc octoate, bismuth neodecanoate, triethylenediamine, dibutyltin maleate, dibutyltin diacetate; The hydrophilic chain extender is one or more of 2,2-dimethylol propionic acid, 2,2-dimethylol butyric acid, tartaric acid, N,N-dihydroxymonomaleamic acid, 1,2-dihydroxy-3-propanesulfonic acid sodium, 1,4-butanediol-2-sulfonic acid sodium; The solvent is acetone; the polyhydric alcohol and the hydrophilic chain extender need to be vacuum dehydrated at a temperature of 50-120°C and a vacuum degree of -0.09 to -0.10 MPa for 1-3 h.

9. The method of claim 1, wherein the method is characterized by, In step c, the fluorine-containing alcohol is one or more of perfluoroalkyl ethanol, 2,2,3,3-tetrafluoropropanol, 2-perfluoropropoxy-2,3,3,3-tetrafluoropropanol, 2,2,3,4,4,4-hexafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 1H,1H,2H,2H-perfluorooctanol, 1H,1H-perfluoro-3,5,5-trimethyl-1-hexanol, hexafluoropropylene oxide dimer alcohol; The neutralizing agent is one or more of sodium hydroxide, triethylamine, N,N dimethyl ethanolamine.

10. The method of claim 1, wherein the method is characterized by, In step d, the thickening agent is one or more of Acrysol RM-8W, Acrysol RM-12W, and ADEKA NOL UH series products. The leveling agent is one or more of TEGO Glide 100, TEGO Glide 410, TEGO flow 425, TEGO Glide 450, TEGO Glide 496, TEGO Glide ZG 400; The defoaming agent is one or more of silicone defoaming agents ACP-1400, ACP-0544, AFE-1430, AFE-0500, AFE-0800, KS66, UNIQFOAM 290W; The wet dispersing agent is one or more of water-based wet dispersing agents DISPERBYK-180, DISPERBYK-182, DISPERBYK-190, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2055; The bactericidal preservative is one or more of Clariant Nipacide BNPD 20, Clariant Nipacide HF-I, Clariant Nipacide CI 15 MV, Clariant Nipacide IPBC 10.

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