Hydrophobic bio-based polyurethane acrylic acid matting resin emulsion and preparation method thereof

Abstract

The invention belongs to the technical field of modified bio-based polyurethane and emulsion preparation, and discloses a hydrophobic bio-based polyurethane acrylic acid matting resin emulsion and a preparation method thereof. The preparation method comprises the following steps: mixing, heating and stirring methanol, epoxidized soybean oil and a catalyst to obtain hydroxyl soybean oil; mixing and heating the obtained hydroxyl soybean oil, isocyanate, a hydrophilic chain extender and a catalyst for reaction, then adding hydroxyethyl acrylate or hydroxypropyl acrylate for blocking, finally neutralizing with triethylamine, adding a proper amount of water after the reaction is finished, and stirring at a high speed to obtain a reaction type water-based bio-based polyurethane emulsion; and adding an acrylate monomer, an emulsifier and an initiator into the reaction type water-based bio-based polyurethane emulsion, and carrying out heating reaction to obtain the hydrophobic bio-based polyurethane acrylic acid matting resin emulsion. The self-extinction resin with low gloss, good hydrophobicity and good mechanical properties is obtained.

Description

Technical Field

[0001] The invention discloses a hydrophobic bio-based polyurethane acrylic matting resin emulsion and a preparation method thereof, belonging to the technical field of modified bio-based polyurethane and emulsion preparation. Background Art

[0002] Matting is widely used in daily life. Low-gloss coatings have attracted the interest of surface scientists in order to reduce light reflection and avoid light pollution. Low-gloss coatings offer significant advantages in several different fields, including aircraft hulls, leather surfaces, vehicle interiors, paper, textiles, wood, schools, and hospitals. Low-gloss coatings can reduce light reflection, avoid eye irritation, and allow people to better focus on their work. Furthermore, for safety reasons, high-gloss coatings are generally avoided on high-rise buildings to prevent glare and irritation to pedestrians and drivers. From an economic perspective, low-gloss coatings can perfectly conceal scratches, dents, and stains on substrates. As aesthetic preferences shift, more and more people are choosing low-gloss coatings.

[0003] The principle of matting, or low gloss, is to reduce light reflection by creating a rough surface. Traditionally, matting agents, such as paraffin wax, montmorillonite, and silica, have been added to the paint. However, this method has numerous drawbacks, including the high dosage and poor compatibility of the matting agent with the paint. While matting is achieved, poor dispersion creates an uneven surface, and excessive addition can easily lead to widespread flaking.

[0004] To address the above-mentioned problems, the research on self-matting coatings has become a hot topic among scientific researchers in recent years. Currently, matting coating products are mainly based on water-based acrylic coatings and water-based polyurethane coatings. Water-based polyurethane has advantages such as good wear resistance, diverse processing properties, adhesion, flexibility, and weather resistance, but poor heat resistance and resistance to strong acids and alkalis. Polyacrylate has advantages such as good oil resistance and heat resistance, but also has disadvantages such as poor processing properties and poor wear resistance. Polyurethane acrylic resin has advantages such as excellent wear resistance, mechanical properties, and resistance to chemical solvents. Combining the two can give full play to the advantages of both. For example, the patent (publication number CN111848914A) discloses a self-matting light-cured water-based polyurethane acrylate cured film with low water absorption and a preparation method thereof. The inventors used alicyclic diisocyanates, oligomeric polyester diols, and hydroxyl-terminated polydimethylsiloxane as the main polymerization monomers to obtain an isocyanate-terminated prepolymer I; then added a capping agent and a polymerization inhibitor to react to obtain a prepolymer II; finally, the prepolymer II was neutralized and emulsified to obtain a self-matting light-curing waterborne polyurethane acrylate emulsion. The matt resin prepared by this method has good low water absorption. Patent (CN105694651A) discloses a method for preparing a water-based self-crosslinking acrylic modified polyurethane matte resin. However, using bio-based epoxy soybean oil as the main raw material to synthesize polyurethane and then using fluorine-containing acrylic modified polyurethane to prepare a hydrophobic matt resin emulsion has not been seen in the prior art. Summary of the Invention

[0005] To overcome the shortcomings and deficiencies of the aforementioned prior art, the primary objective of the present invention is to provide an acrylic-modified waterborne bio-based polyurethane emulsion. This emulsion uses epoxidized soybean oil as the primary raw material to synthesize a reactive waterborne polyurethane, which is then copolymerized with a fluorinated acrylic monomer to produce a hydrophobic matte resin emulsion. This preparation method is environmentally friendly, simple to operate, and uses inexpensive raw materials. The resulting matte resin film exhibits excellent properties, including good hydrophobicity, low gloss, toughness, and acid and alkali resistance.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned emulsion based on water-based bio-based polyurethane modified with fluorine-containing acrylic monomers.

[0007] The technical scheme of the above-mentioned preparation method is as follows:

[0008] A method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion comprises the following steps:

[0009] (1) Preparation of hydroxy soybean oil:

[0010] The epoxidized soybean oil, methanol and catalyst are reacted at 30-50° C. for 4-12 hours, and the methanol is removed by rotary evaporation after the reaction to obtain hydroxylated soybean oil with a hydroxyl value of 90-130 mgKOH / g.

[0011] The catalyst in step (1) is fluoroboric acid, dilute sulfuric acid, triethylamine, tetrabutylammonium bromide, triphenylphosphine, etc., and the mass ratio of the catalyst is 0.2% to 1%; the mass ratio of epoxidized soybean oil to methanol is 1:1 to 4:1.

[0012] (2) Preparation of reactive waterborne bio-based polyurethane emulsion:

[0013] The hydroxy soybean oil obtained in step (1) is heated to 70-100° C. under nitrogen protection with isocyanate, hydrophilic chain extender and catalyst, and kept warm for 3-7 hours. After the reaction is settled, the temperature is lowered to 50-70° C., and hydroxyl-containing acrylate is added and kept warm for 1-3 hours. After the reaction is completed, the reaction temperature is lowered to 25-45° C., triethylamine is added to neutralize the carboxylic acid in the hydrophilic chain extender, and the mixture is stirred for 1-2 hours. An appropriate amount of deionized water is added and stirred at high speed to obtain a reactive waterborne bio-based polyurethane emulsion.

[0014] The isocyanate index R (nNCO / nOH) value is 1.1 to 2.0 and is selected from isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI) and 2,4-toluene diisocyanate (TDI);

[0015] The hydrophilic chain extender is 2,2-dimethylolpropionic acid (DMPA) or 2,2-dimethylbutyric acid (DMBA);

[0016] The hydroxyl-containing acrylate is hydroxyethyl acrylate or hydroxypropyl acrylate; the usage amount is 3 to 10%.

[0017] Triethylamine is 1.2-2.0% by weight of the hydrophilic chain extender;

[0018] The catalyst is dibutyltin dilaurate (DBTDL), and the dosage is 0.2% to 1%;

[0019] (3) Preparation of a hydrophobic hybrid emulsion: pre-emulsify the emulsion obtained in step (2) with an acrylic monomer and an emulsifier at 25-50° C. for 30-120 min, take out 20-50% of the pre-emulsion, and then heat the reaction system to 65-100° C.; add an initiator, dropwise add for 30-120 min, and keep warm for 30-120 min; then heat the system to 65-100° C., and simultaneously dropwise add the remaining initiator and the remaining pre-emulsion, dropwise add for 1-3 h, and finally keep warm for 1-3 h. After the heat preservation reaction, a hydrophobic self-matting resin emulsion is obtained.

[0020] Acrylate monomers include hard monomers, soft monomers and fluorine-containing monomers, accounting for 30-70% by mass, and the mass ratio of hard monomer: soft monomer: fluorine monomer is (1.0-1.5): (2.0-3.0): (1.0-2.0);

[0021] The emulsifier is a combination of anionic and nonionic, with a total dosage of 0.4-2%;

[0022] The initiator is one of potassium persulfate, ammonium persulfate, sodium persulfate, azobisisobutyl, etc., and the dosage is 0.2-1%.

[0023] The hard monomer is one or more of methyl methacrylate (MMA), butyl methacrylate (BMA), isobutyl methacrylate (i-BMA), and styrene (St); the soft monomer is one or more of isooctyl acrylate (2-EHA) and butyl acrylate (BA); the fluorine-containing monomer is one or more of trifluoroethyl methacrylate (TFEMA), hexafluorobutyl methacrylate (HFBMA), 1H,1H-perfluorooctanoic acid methacrylate, 1H,1H,11H-perfluoroundecyl acrylate, and 1H,1H,2H,2H-nonafluorohexyl acrylate.

[0024] The anionic emulsifier is one of sodium vinyl sulfonate, SDS, and SDBS, and the amount used is 0.2-1%. The nonionic emulsifier is one of OP-10, AEO9, AEO7, Tween 80, and Tween 60, and the amount used is 0.2-1%.

[0025] It should be noted that the above percentage contents are all by weight.

[0026] The beneficial effects of the present invention are:

[0027] Using bio-based epoxidized soybean oil as the primary raw material, acrylate monomers were grafted onto the synthesized bio-based polyurethane structure. Phase inversion emulsification technology was used to produce an oil-in-water, hydrophobic bio-based polyurethane-acrylic hybrid emulsion. By varying the ratio of the synthesized reactive bio-based polyurethane to acrylate monomers, the amount of acrylate monomers, the type and amount of emulsifier, the emulsification temperature, and the stirring speed, a self-matting resin emulsion with low gloss, excellent hydrophobicity, and good mechanical properties was obtained. The use of epoxidized soybean oil as the primary raw material, due to its environmentally friendly and low price, significantly reduced production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an emulsion diagram of the reactive bio-based polyurethane in Example 1;

[0029] Figure 2 This is the film obtained after the hydrophobic polyurethane acrylic matting resin emulsion in Example 1 is dried. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] Example 1:

[0032] 1. Preparation of hydroxylated soybean oil

[0033] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat to 40°C under nitrogen until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0034] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0035] A four-necked flask was charged with 50g of hydroxylated soybean oil, 30.8g of TDI, 8.52g of DMPA, and 0.83g of a catalyst. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was then added and stirred at 6000 rpm to produce a reactive waterborne bio-based polyurethane emulsion.

[0036] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0037] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% SDS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0038] like Figure 1 Shown is a latex diagram of a reactive bio-based polyurethane. Figure 2 The film is made of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion.

[0039] Example 2:

[0040] 1. Preparation of hydroxylated soybean oil

[0041] Add 100g of epoxidized soybean oil, 25g of methanol, and 0.4g of catalyst to a four-necked flask and heat to 50°C under nitrogen until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0042] 2. Preparation of a Reactive Waterborne Bio-based Polyurethane Emulsion: 50g of hydroxylated soybean oil, 30.8g of TDI, 8.52g of DMPA, and 0.83g of a catalyst were added to a four-necked flask and heated to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was added and the mixture was stirred at 6000 rpm to obtain a reactive waterborne bio-based polyurethane emulsion.

[0043] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0044] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% SDS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0045] Example 3:

[0046] 1. Preparation of hydroxylated soybean oil

[0047] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0048] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0049] A four-necked flask was charged with 50g of hydroxylated soybean oil, 37.0g of TDI, 8.52g of DMPA, and 0.83g of a catalyst. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 9.1g of triethylamine was added. 240g of deionized water was then added and stirred at 6000 rpm to obtain a reactive waterborne bio-based polyurethane emulsion.

[0050] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0051] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% SDS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0052] Example 4:

[0053] 1. Preparation of hydroxylated soybean oil

[0054] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0055] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0056] To a four-necked flask, 50g of hydroxylated soybean oil, 30.8g of HDI, 8.52g of DMPA, and 0.83g of catalyst were added. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was added and the mixture was stirred at 6000 rpm to obtain a reactive waterborne bio-based polyurethane emulsion.

[0057] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0058] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% SDS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0059] Example 5:

[0060] 1. Preparation of hydroxylated soybean oil

[0061] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0062] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0063] A four-necked flask was charged with 50g of hydroxylated soybean oil, 30.8g of TDI, 8.52g of DMPA, and 0.83g of a catalyst. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was then added and stirred at 6000 rpm to produce a reactive waterborne bio-based polyurethane emulsion.

[0064] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0065] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 30 g of MMA, 10 g of St, 30 g of BA and 30 g of TFEMA, 0.8% SDS, and 0.4% AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0066] Example 6:

[0067] 1. Preparation of hydroxylated soybean oil

[0068] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0069] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0070] A four-necked flask was charged with 50g of hydroxylated soybean oil, 30.8g of TDI, 8.52g of DMPA, and 0.83g of a catalyst. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was then added and stirred at 6000 rpm to produce a reactive waterborne bio-based polyurethane emulsion.

[0071] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0072] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 30 g of MMA, 10 g of St, 20 g of BA and 40 g of TFEMA, 0.8% SDS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0073] Example 7:

[0074] 1. Preparation of hydroxylated soybean oil

[0075] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0076] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0077] A four-necked flask was charged with 50g of hydroxylated soybean oil, 30.8g of TDI, 8.52g of DMPA, and 0.83g of a catalyst. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was then added and stirred at 6000 rpm to produce a reactive waterborne bio-based polyurethane emulsion.

[0078] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0079] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 25 g of MMA, 10 g of St, 35 g of BA and 30 g of 1H,1H,11H-perfluoroundecyl acrylate, 0.8% SDS, and 0.4% AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0080] Example 8:

[0081] 1. Preparation of hydroxylated soybean oil

[0082] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0083] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0084] To a four-necked flask, 50g of hydroxylated soybean oil, 30.8g of HDI, 8.52g of DMPA, and 0.83g of catalyst were added. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was added and the mixture was stirred at 6000 rpm to obtain a reactive waterborne bio-based polyurethane emulsion.

[0085] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0086] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% of SDBS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0087] Example 9:

[0088] 1. Preparation of hydroxylated soybean oil

[0089] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0090] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0091] To a four-necked flask, 50g of hydroxylated soybean oil, 30.8g of HDI, 8.52g of DMPA, and 0.83g of catalyst were added. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was added and the mixture was stirred at 6000 rpm to obtain a reactive waterborne bio-based polyurethane emulsion.

[0092] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0093] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% SDS, and 0.4% of Tween 80 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80° C., 0.1 g of potassium persulfate solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80° C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0094] Example 10:

[0095] 1. Preparation of hydroxylated soybean oil

[0096] Add 50g of epoxidized soybean oil, 25g of methanol, and 0.225g of catalyst to a four-necked flask and heat under nitrogen to 50°C until the hydroxyl value reaches 90-130mgKOH / g. After cooling to room temperature, remove excess methanol by rotary evaporation at 40°C.

[0097] 2. Preparation of reactive waterborne bio-based polyurethane emulsion

[0098] To a four-necked flask, 50g of hydroxylated soybean oil, 30.8g of HDI, 8.52g of DMPA, and 0.83g of catalyst were added. The temperature was raised to 70°C under nitrogen. After the reaction was complete, the temperature was lowered to 60°C and 16g of hydroxypropyl acrylate was added with stirring. After the reaction was complete, the temperature was lowered to room temperature and 7.6g of triethylamine was added. 240g of deionized water was added and the mixture was stirred at 6000 rpm to obtain a reactive waterborne bio-based polyurethane emulsion.

[0099] 3. Preparation of hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsion

[0100] 100 g of the reactive water-based bio-based polyurethane emulsion obtained above was placed in a four-necked flask, and 35 g of MMA, 15 g of St, 30 g of BA and 20 g of TFEMA, 0.8% SDS, and 0.4% of AEO9 were added and emulsified at room temperature. 40% of the pre-emulsion was taken out, and an appropriate amount of water was added to the four-necked flask. The solid content was adjusted to 35%, the temperature was raised to 80°C, 0.1 g of azobisisobutyronitrile solution was added dropwise, and 40% of the pre-emulsion was added dropwise at the same time. The mixture was kept warm at 80°C. After the reaction was completed, a hydrophobic bio-based water-based polyurethane acrylic matting resin emulsion was obtained.

[0101] The extinction value and contact angle experiments were conducted on the hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsions prepared in the above 10 examples. The specific experimental results are shown in Table 1.

[0102] Table 1 Example test results

[0103] Instance number Extinction value contact angle Water-based matting resin BY-992 42 50 1 35 85 2 35 85 3 30 90 4 34 85 5 30 95 6 26 110 7 20 138 8 18 142 9 36 85 10 36 85

[0104] The experimental data in Table 1 show that the hydrophobic bio-based waterborne polyurethane acrylic matting resin emulsions prepared in the 10 examples have better matting effect and better hydrophobic properties than the waterborne matting resin BY-992 on the market.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion, characterized in that: The following steps are involved: (1) Preparation of hydroxy soybean oil: The epoxidized soybean oil, methanol and catalyst are reacted at 30-50° C. for 4-12 hours, and the methanol is removed by rotary evaporation after the reaction to obtain hydroxylated soybean oil with a hydroxyl value of 90-130 mgKOH / g. (2) Preparation of reactive waterborne bio-based polyurethane emulsion: The hydroxy soybean oil obtained in step (1) is heated to 70-100° C. under nitrogen protection with isocyanate, hydrophilic chain extender and catalyst, and kept warm for 3-7 hours. After the reaction is settled, the temperature is lowered to 50-70° C., and hydroxyl-containing acrylate is added and kept warm for 1-3 hours. After the reaction is completed, the reaction temperature is lowered to 25-45° C., triethylamine is added to neutralize the carboxylic acid in the hydrophilic chain extender, and the mixture is stirred for 1-2 hours. An appropriate amount of deionized water is added and stirred at high speed to obtain a reactive waterborne bio-based polyurethane emulsion. (3) Preparation of a hydrophobic hybrid emulsion: pre-emulsify the emulsion obtained in step (2) with an acrylic monomer and an emulsifier at 25-50° C. for 30-120 min, take out 20-50% of the pre-emulsion, and then heat the reaction system to 65-100° C.; add an initiator, dropwise add for 30-120 min, and keep warm for 30-120 min; then heat the system to 65-100° C., and simultaneously dropwise add the remaining initiator and the remaining pre-emulsion, dropwise add for 1-3 h, and finally keep warm for 1-3 h. After the heat preservation reaction, a hydrophobic self-matting resin emulsion is obtained.

2. The method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion according to claim 1, characterized in that: In the step (1), the catalyst is fluoroboric acid, dilute sulfuric acid, triethylamine, triphenylphosphine or tetrabutylammonium bromide, and the mass ratio of the catalyst is 0.2% to 1%; the mass ratio of the epoxidized soybean oil to the methanol is 1:1 to 4:

1.

3. The method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion according to claim 1, characterized in that: In the step (2): The isocyanate has an R (nNCO / nOH) value of 1.1 to 2.0 and is selected from IPDI, HDI, MDI or TDI; The hydrophilic chain extender is DMPA or DMBA; The hydroxyl-containing acrylate is hydroxyethyl acrylate or hydroxypropyl acrylate; the usage amount is 3 to 10%. Triethylamine is 1.2-2.0% by weight of the hydrophilic chain extender; The catalyst is DBTDL, and the dosage is 0.2% to 1%.

4. The method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion according to claim 1, characterized in that: In the step (3): Acrylate monomers include hard monomers, soft monomers and fluorine-containing monomers, accounting for 30-70% by mass, and the mass ratio of hard monomer: soft monomer: fluorine monomer is (1.0-1.5): (2.0-3.0): (1.0-2.0); The emulsifier is a combination of anionic and nonionic, with a total dosage of 0.4-2%; The initiator is one of potassium persulfate, ammonium persulfate, sodium persulfate, azobisisobutyl, etc., and the dosage is 0.2-1%.

5. The method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion according to claim 4, characterized in that: The hard monomer is one or more of MMA, BMA, i-BMA, and St; the soft monomer is one or more of 2-EHA and BA; and the fluorine-containing monomer is one or more of TFEMA, HFBMA, 1H,1H-perfluorooctanoic acid methacrylate, 1H,1H,11H-perfluoroundecyl acrylate, and 1H,1H,2H,2H-nonafluorohexyl acrylate.

6. The method for preparing a hydrophobic bio-based polyurethane acrylic matting resin emulsion according to claim 4, characterized in that: The anionic emulsifier is one of sodium vinyl sulfonate, SDS, and SDBS, and the amount used is 0.2-1%. The nonionic emulsifier is one of OP-10, AEO9, AEO7, Tween 80, and Tween 60, and the amount used is 0.2-1%.

7. A hydrophobic bio-based polyurethane acrylic matting resin emulsion, characterized in that Obtained according to the preparation method according to any one of claims 1 to 6.

8. Use of the hydrophobic bio-based polyurethane acrylic matting resin emulsion according to claim 7 in matting coatings.

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